Cycloolefin polymerization catalyst composition

ABSTRACT

A polymerization catalyst composition including   &lt;IMAGE&gt;   wherein R is an alkyl group having 3 to 20 carbon atoms; m is 4 or 6 and n is 0 or 1. Preferably the composition also includes,   &lt;IMAGE&gt;  wherein R1 and R2 are independently hydrogen, an alkyl or alkoxy group of form 1 to 5 carbons. Preferably r is 1; m is 4 and R is nonyl and the molar ratio of WClmOn to   &lt;IMAGE&gt;  is from about 1:1 to about 1:3.

This application is a continuation-in-part of application Ser. No.472,684 filed Mar. 7, 1983, now U.S. Pat. No. 4,520,181, which is adivision of application Ser. No. 342,453 filed Jan. 25, 1982 and nowU.S. Pat. No. 4,400,340 and a continuation-in-part of application Ser.No. 552,195 filed Nov. 15, 1983 and now U.S. Pat. No. 4,485,208 which isa division of application Ser. No. 378,449 filed May 14, 1982, now U.S.Pat. No. 4,436,858.

BACKGROUND OF THE INVENTION

This invention relates to novel polymer product compositions,polymerization feed compositions and monomer purification therefor. Inparticular, it relates to a crosslinked, high modulus, high impactstrength, thermoset polymer of polycycloolefin units which is formed viaa metathesis-catalyst system.

Distillation is commonly used in the preparation of polycycloolefins,for example dicyclopentadiene. Various purities of dicyclopentadiene areavailable. The invention preferably uses economically available purifieddicyclopentadiene which is readily polymerized. Purifieddicyclopentadiene forms a substantially cross-linked thermoset polymerwhen polymerized as disclosed herein.

Any good thermoset polymer should meet at least two criteria. It shouldhave desirable physical properties and it should lend itself to easysynthesis and forming. Among the most desirable physical properties formany polymers is a combination of high impact strength and high modulus.A standard test for impact strength is the notched Izod impact test,ASTM No. D-256. For an unreinforced thermoset polymer to have goodimpact strength, its notched Izod impact should be at least 1.5 ft.lb./in. notch. It is desirable that this good impact strength becombined with a modulus of at least about 150,000 psi at ambienttemperature. Thermoset polymers with high impact strength and highmodulus find useful applications as engineering plastics in sucharticles of manufacture as automobiles, appliances and sports equipment.Among the critical factors in the synthesis and forming of a thermosetpolymer are the conditions required to make the polymer set up or gel.Many thermoset polymers require considerable time, elevated temperatureand pressure, or additional steps after the reactants are mixed beforethe setting is complete.

A thermoset homopolymer having high impact strength and high modulus hasbeen described by Klosiewicz in U.S. Pat. No. 4,400,340, U.S. Pat. Nos.4,469,809 and 4,436,858 (with plasticizer) and by Leach in U.S. Pat. No.4,458,037 (a foam). Characteristics of thermoset polymers includeinsolubility in common solvents such as gasoline, naphtha, chlorinatedhydrocarbons, and aromatics as well as resistance to flow at elevatedtemperatures.

Work has been done on the metathesis copolymerization ofdicyclopentadiene with one or more other monomers to produce solublecopolymers. This copolymer formation has resulted in the production ofunwanted insoluble by-products. U.S. Pat. No. 4,002,815, for instance,which teaches the copolymerization of cyclopentene withdicyclopentadiene, describes an insoluble by-product and suggests thatthe by-product could be a gel of a dicyclopentadiene homopolymer.

Some other work, usually in an attempt to produce soluble polymers, hasbeen done on the metathesis polymerization of dicyclopentadiene.Japanese unexamined published patent applications KOKAI No. 53-92000 andNo. 53-111399 disclose soluble polymers of dicyclopentadiene. Severalsyntheses of soluble polymers of dicyclopentadiene have producedinsoluble by-products. Takata et al, J. Chem. Soc. Japan Inc. Chem.Sect., 69, 711 (1966), discloses the production of an insolublepolymerized dicyclopentadiene by-product from the Ziegler-Nattacatalyzed polymerization of dicyclopentadiene; Oshika et al, Bulletin ofthe Chemical Society of Japan, discloses the production of an insolublepolymer when dicyclopentadiene is polymerized with WCl₆, AlEt₃ /TiCl₄ orAlEt₃ /MoCO₅ ; and Dall Asta et al, Die Makromolecular Chemie 130, 153(1969), discloses an insoluble by-product produced when a WCl₆ /AlEt₂ Clcatalyst system is used to form polymerized dicyclopentadiene.

In U.S. Pat. No. 3,627,739, dicyclopentadiene is gelled with unactivatedcatalyst and then heated for an hour.

Pampus et al in U.S. Pat. No. 3,873,644 discloses a method of producinggraft polymers from a cyclic olefin to obtain thermoplastic products ofhigh impact strength.

Ofstead in U.S. Pat. Nos. 4,020,254 and 3,935,179 disclose metathesispolymerization of cycloolefins to obtain a rubbery polymer. Streck et alin U.S. Pat. Nos. 3,974,092 and 3,974,094 discloses a catalyst forpreparation of polyalkenamers. Each discloses polyalkenamers of lowreduced melt viscosity. Percent gel obtained using the system of Strecket al is very low. A typical percent gel is about 2 to 6% with 14 beingthe highest value disclosed. Wilkes in U.S. Pat. No. 3,084,147 disclosesthermalpolymerization of dicyclopentadiene. The thermal polymerizationis carried out in a nonpolymerizable solvent at about 500° to 550° F.

Stafford in U.S. Pat. No. 3,446,785 discloses a polymerization ofolefins. The polymerization discloses the production of a product whichis a viscous liquid polymer or a brittle, semi-solid polymer.

Nutzel et al in U.S. Pat. No. 3,684,787 discloses preparation ofpolyalkenamers. The polymers can be isolated by pouring the solution ofpolymer into 3 to 5 times its quantity of a solution of a lower alcoholin which an age resister is dissolved. Alternatively, the solution canbe introduced into boiling water and the solvent removed with steam.Mensel states in column 1, line 19 that crosslinked products are of noindustrial interest. The polymers obtained have a rubber-like character.

Vergne et al in U.S. Pat. No. 3,557,072 discloses plastomers derivedfrom dimethanooctahydronaphthalene and their method of manufacture.Amorphous polymers are obtained in the form of a hard white mass whichis washed with methanol and then ground and dried to a white powder.

Tenney et al and Tenney alone in U.S. Pat. Nos. 4,136,247, 4,136,248,4,136,249 and 4,178,424 disclose ring-opened cycloolefin polymers andcopolymers. These polymer products are thermoplastics which can bethermoformed.

Minchak and Minchak et al respectively in U.S. Pat. Nos. 4,002,815 and4,380,617 each disclose polymerization of cycloolefins to form polymerswhich may be isolated by precipitation using an alcohol or by steam orhot water stripping. The polymers produced have inherent viscositiesfrom about 0.1 to about 10 and are greater than 90% soluble in solvent.Viscous cements and plastic polymers solidify in from about 30 minutesto 180 minutes. The reaction is short stopped in less than 2 hours byaddition of an alcohol. Minchak in U.S. Pat. No. 4,426,502 disclosesbulk polymerization of cycloolefins by reaction injection molding inless than about 2 minutes using an organoammonium molybdate or tungstatecatalyst.

DeWitt et al in U.S. Pat. No. 4,418,179 discloses impact modificationcycloolefins by polymerization using an organoammonium molybdate ortungstate catalysts in the less than 2 minutes using reaction injectionmolding.

Oshika et al in the Bulletin of the Chemical Society of Japan, line 41,pages 211-217 (1968) discloses ring opening polymerization of norborneneand its derivatives by MoCl₅, WCl₆ and ReCl₅ catalysts. Dark crudepolymer is obtained which is dissolved and reprecipitated with methanol.

U.S. Pat. No. 4,002,815 discloses the use of a metathesis-catalystsystem which employs a dialkylaluminum iodide, an alkylaluminum diiodideor a mixture of trialkylaluminum compounds with elemental iodine toproduce substantially gel-free copolymers of cyclopentene anddicyclopentadiene.

U.S. Pat. No. 4,069,376 discloses the use of a three component catalystcomprised of a soluble tungsten compound, a dialkylaluminum chloride oralkylaluminum dichloride, and a dialkylaluminum iodide or alkylaluminumdiiodide to produce substantially gel-free norbornene-dicyclopentadienecopolymers.

U.S. application Ser. No. 526,835 filed Aug. 26, 1983 and now U.S. Pat.No. 4,535,097 and assigned to the same assignee, discloses a cellularcrosslinked poly(dicyclopentadiene) which is made with ametathesis-catalyst system. The cellular polymer is made by injectingthe catalyst system, which includes an alkylaluminum activator, into areaction vessel which is preheated, preferably to a temperature fromabout 100° C. to about 125° C.

Not only is it desirable that the thermoset polymer have high impactstrength, but it is also desirable that it be easily synthesized andformed. A reaction injection molding (sometimes hereinafter referred toas RIM) process achieves this second goal by in-mold polymerization. Theprocess involves the mixing of two or more low viscosity reactivestreams. The combined streams are then injected into a mold where theyquickly set up into a solid infusible mass. For a RIM system to be ofuse with a particular polymer, certain requirements must be met: (1) theindividual streams must be stable and must have a reasonable shelf-lifeunder ambient conditions; (2) it must be possible to mix the streamsthoroughly without their setting up in the mixing head; (3) wheninjected into the mold, the materials must set up to a solid systemrapidly; and (4) any additives-fillers, stabilizers, pigments,etc.--must be added before the material sets up. Therefore, theadditives selected must not interfere with the polymerization reaction.

Interpenetrating polymer networks (IPNs) are a type of polymer alloyconsisting of two (or more) crosslinked polymers. They are more-or-lessintimate mixtures of two or more distinct, crosslinked polymer networksheld together by permanent entanglements with few, if any covalent bondsbetween the polymers. The entanglements in IPNs must be of a permanentnature and are made so by self-crosslinking of the two polymers. Theyare introduced either by swelling a crosslinked polymer with monomer andthe crosslinking agent of another polymer, and curing the swollenpolymer in situ or by mixing the linear polymer, prepolymers, ormonomers in some liquid form solution, or bulk, together withcrosslinking agents, evaporating the vehicle (if any), and curing thecomponent polymers simultaneously.

IPNs possess several interesting characteristics in comparison to normalpolyblends. Formation of IPNs is the only way to intimately combinecrosslinked polymers, the resulting mixture exhibiting (at worst) onlylimited phase separation. Normal blending or mixing of polymers resultsin a multiphase morphology due to the well-known thermodynamicincompatibility of polymers. However, if mixing is accomplishedsimultaneously with crosslinking, phase separation may be kineticallycontrolled by permanent interlocking of entangled chains.

Molecular and supramolecular perspectives are believed to be importantin considering interpenetrating networks. On linked polymer networksintermeshed through molecular chain segment entanglements. These aretotally non-separable without chain breaking (i.e. degradation). Asemi-interpenetrating network (SIPN) then is a crosslinked networkhaving a non-crosslinked polymer dispersed through it on a molecularscale. These in theory are separable without bond breaking. Neither theinterpenetrating network nor the SIPN represents a heterophase polymerstructure in a morphological or supramolecular sense.

The supramolecular scale microscopically observable heterophases arepresent SIPN and IPN. In this context an interpenetrating network is anysystem of two polymers where the supramolecular structure involves twointermeshed continuous polymer phases irrespective of whether or notthey are crosslinked.

Because molecular mixing of dissimilar uncrosslinked polymers isthermodynamically unfavorable (for entropic reasons) it is unusual toform a stable, molecular IPN from two uncrosslinked polymers. Theygenerally will separate into a heterophase polymer system which might ormight not be a supramolecular IPN.

The forming of supramolecular interpenetrating networks of twouncrosslinked polymers is called polymer blends. "Coreacted" polymers isa process which results in block copolymers and sometimes results inheterophase polymer systems which could exhibit supramolecular IPNmorphology, depending on block length.

SUMMARY OF THE INVENTION

A polymerization catalyst composition including ##STR4## wherein R is analkyl group having 3 to 20 carbon atoms; m is 4 or 6 and n is 0 or 1.Preferably the composition also includes, ##STR5## wherein R₁ and R₂ areindependently hydrogen, an alkyl or alkoxy group of form 1 to 5 carbons.Preferably r is 1; m is 4 and R is nonyl and the molar ratio of WCl_(m)O_(n) to ##STR6## is from about 1:1 to about 1:3.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, unless otherwise specified, percentage of materials arein percent by weight.

As used herein, unless otherwise specified, "solvent" means a fluid inwhich the monomer or catalyst is readily soluble.

Preferably, the composition used to make the polymers of the presentinvention have from 0 to about 2 percent solvent. Particularly formaking solid (unfoamed) polymer the less solvent present the fewer voidsformed in the product. In general, and particularly in the formation ofmolded noncellular solid polymer, the polymerization mixture is about 88to 98 percent polycyclic olefin monomer, on a blowing agent free basis.Preferably, the polymerization solution is about 0 to 10 percentelastomer. The solvent present, if any, is probably from the catalystsolution added to the monomer to make to polymerization solution.

Throughout this disclosure, percentages are weight by weight unlessotherwise specified.

Cycloolefins, for example, dicyclopentadiene can be polymerized in sucha manner that the resulting product is a thermoset homopolymer havinghigh impact strength and high modulus. Dicyclopentadiene, the preferredmonomer, is commercially available endo-DCPD (3a,4,7,7atetrahydro-4,7-methano-1H-indene). The exo-isomer, while notcommercially available, can be used just as well. The preferredcommercially available material has a purity of 96-97%. Commerciallyavailable material should be purified in order to prevent impuritiesfrom inhibiting the polymerization. The low boiling fraction should beremoved. This can be done by stripping away several percent of theunsaturated four to six carbon atom volatiles, i.e., the volatilesdistilled below 100° C. at about 90±3 torr absolute pressure. It isoften desirable to purify the starting material even further bytreatment with an absorbent such as molecular sieves, alumina or silicagel. Additionally, the water content of the starting material should bebelow about 100 ppm. The presence of water interferes withpolymerization by hydrolysis of both the catalyst and the activatorcomponents of the catalyst system. Water can be removed by azeotropicdistillation under reduced pressure.

The polymerization of the purified cyclolefin containing at least 50percent dicyclopentadiene is catalyzed by a two part metathesis-catalystsystem. One part contains a tungsten containing catalyst, such as atungsten halide or tungsten oxy halide, preferably WCl₆, WOCl₄ or amixture thereof. The other part contains an activator such as tetraalkyltin or an alkylaluminum compound. The alkylaluminum compound can be atrialkylaluminum, an alkylaluminum dihalide or a dialkylaluminum halidewhere the alkyl group contains one to ten carbon atoms. In the preferredactivator the alkyl group is octyl.

One part of the catalyst system comprises the tungsten containingcatalyst, preferably in solution with dicyclopentadiene monomer. Thetungsten compound, if unmodified, will rapidly polymerize the monomer.Consequently, the tungsten compound should first be suspended in a smallamount of a suitable solvent. The solvent must not be susceptible toreacting with the tungsten compound. For instance, where a tungstenhalide is employed the solvent must not be susceptible to halogenation.Examples of preferred solvents are benzene, toluene, xylene,chlorobenzene, dichlorobenzene, and trichlorobenzene. Sufficient solventshould be added so that the tungsten compound concentration is betweenabout 0.1 and 1.0 mole per liter of solution.

The tungsten compound can be solubilized by the addition of a smallamount of an alcoholic or a phenolic compound. Phenolic compounds arepreferred. Suitable phenolic compounds include phenol, alkyl phenols,and halogenated phenols, with tert-butyl phenol, tert-octyl phenol andnonyl phenol being most preferred. The preferred molar ratio of tungstencompound/phenolic compound is from about 1:1 to about 1:3. The tungstencompound/phenolic compound solution can be made by adding the phenoliccompound to a tungsten compound/organic solvent slurry, stirring thesolution and then blowing a stream of a dry inert gas through thesolution to remove any hydrogen chloride. Alternatively, a phenolicsalt, such as a lithium or sodium phenoxide, can be added to a tungstencompound/organic solvent slurry, the mixture stirred until essentiallyall the tungsten compound is dissolved, and the precipitated inorganicsalt removed by filtration or centrifugation. All of these steps shouldbe carried out in the absence of moisture and air to preventdeactivation of the catalyst.

Stabilization of Catalyst

To prevent premature polymerization of the tungsten compound/monomersolution, which would occur within a matter of hours, from about 1 toabout 5 moles of a Lewis base or a chelating agent can be added per moleof tungsten compound. Preferred chelants include acetylacetones, alkylacetoacetates, where the alkyl group contains from one to ten carbonatoms; preferred Lewis bases are nitriles and ethers such asbenzonitrile and tetrahydrofuran. The improvement in the stability andshelf-life of the tungsten compound/monomer solution is obtained whetherthe complexing agent is added before or after the phenolic compound.When purified cycloolefin, for example dicyclopentadiene is added tothis catalyst solution it forms a solution which is stable and has ashelf-life of several months. The other part of the metathesis-catalystsystem comprises the activator, as described above, preferably indicyclopentadiene monomer.

Induction Time Control

Induction time is the period of time between mixing of catalyst,activator and monomer and the exotherm, which indicates the onset ofexothermic polymerization. If an unmodified activator/monomer solutionis mixed with the catalyst/monomer solution, the polymerization willinitiate spontaneously and instantaneously and the polymer can set up inthe mixing head. The onset of polymerization can be delayed by adding areaction rate moderator to the activator/monomer solution. Ethers,esters, ketones, nitriles and polar cycloolefins can act as moderatorsfor the alkylaluminum compounds. Ethyl benzoate, butyl etherbis(2-methoxyethyl)ether and polar cycloolefin monomers are preferred.The induction time is controlled by varying the specific amount of ratemoderator used. The preferred ratio of the alkylaluminum to moderator isfrom about 1:1.5 to about 1:5 on a molar basis.

Preferably, the polymerization of cycloolefin using activated catalystto form substantially crosslinked polymerized units of cycloolefin issubstantially complete in from about 1 second to about 18 minutes. Morepreferably, this polymerization is substantially complete in from about10 seconds to about 10 minutes. Most preferably, the polymerization issubstantially complete in from about 15 seconds to about five minutes.

The induction time is also temperature dependent. As the temperature atwhich the reaction is carried out is increased the induction time willdecrease. Consequently, to keep the induction time controlled at higherreaction temperatures a less active formulation of the metathesiscatalyst system should be used. One way of reformulating the system isby choice of moderator. Other ways will be readily determinable by oneskilled in the art.

What is ultimately required is that when the catalyst system'scomponents are combined, the resulting cycloolefin (for exampledicyclopentadiene) to tungsten compound ratio will be from about 500:1to about 15,000:1 on a molar basis, preferably 2,000:1 and thedicyclopentadiene to alkylaluminum ratio will be from about 100:1 toabout 2000:1 on a molar basis, preferably about 200:1 to about 500:1. Toillustrate a preferred combination: sufficient dicyclopentadiene isadded to a 0.5 molar tungsten containing catalyst solution prepared asdescribed above, so that the final tungsten compound concentration is0.007 molar. This corresponds to a dicyclopentadiene to tungstencompound ratio of 1000:1. Sufficient dicyclopentadiene is added to thediethylaluminum chloride (Et₂ AlCl) solution, prepared as describedabove, so that the alkylaluminum concentration is 0.048M. Thiscorresponds to a dicyclopentadiene to alkylaluminum ratio of 150:1. Ifthese two streams are mixed in a 1:1 ratio, the final ratio ofdicyclopentadiene to tungsten compound will be 2000:1, the final ratioof dicyclopentadiene to alkylaluminum will be 300:1 and the final ratioof tungsten compound to alkylaluminum will be about 1:7. The illustratedcombination is not the lowest catalyst level at which moldings can bemade, but it is a practical level that provides for excess catalyst ifimpurities in the system consume some of the catalyst components. Ahigher alkylaluminum level will not only increase costs and residualchlorine levels but may result in a less satisfactory cure. Too low atungsten compound concentration results in incomplete conversion. A widerange of alkylaluminum activator to tungsten catalyst formulationsproduce substantially crosslinked polymer products which have goodout-of-mold properties such as tear resistance, stiffness, residualodor, and surface properties.

In a preferred synthesis, the polymerized dicyclopentadiene is made andmolded via the RIM process. The two parts of the metathesis catalystsystem are each mixed with dicyclopentadiene, to form stable solutionswhich are placed in separate vessels. These vessels provide the sourcefor separate streams. The two streams are combined in the RIM machine'smixing head and then injected into a warm mold where they quicklypolymerize into a solid, infusible mass. The invention is not intendedto be limited to systems employing two streams each containing monomer.It will be obvious to one skilled in the art that there may besituations where it is desirable to have monomer incorporated in justone stream or to employ more than two streams where the additionalstreams contain monomer and/or additives.

These streams are completely compatible with conventional RIM equipment.Metathesis catalyzed polymerizations are known to be inhibited by oxygenso it is necessary to store the components under an inert gas but,surprisingly, it is not necessary to blanket the mold with an inert gas.The streams are combined in the mixing head of a RIM machine. Turbulentmixing is easy to achieve because the process involves low viscosity,low molecular weight, rapidly diffusing components. Typically the mixingheads have orifices about 0.032 inch in diameter and a jet velocity ofabout 400 ft/sec. After being combined the mixture is injected into amold maintained at 35°-100° C., preferably 50°-70° C. The mold pressureis in the range of about 10-50 psi. A rapid exothermic reaction occursas the poly(DCPD) sets up. The mold can be opened in as little as 20-30seconds after the combined streams have been injected. In this shorttime heat removal is not complete and the polymer is hot and flexible.The polymer can be removed from the mold immediately while hot or aftercooling. After the polymer has cooled it will become a rigid solid. Thetotal cycle time may be as low as 0.5 minute.

The substantially crosslinked product has a flexural modulus of at leastabout 150,000 to 300,000 psi and a notched Izod impact resistance of atleast about 1.5 ft. lb./in. notch. The polymer product is low inresidual monomer and insoluble in common solvents such as gasoline,naphthas, chlorinated hydrocarbons and aromatics, resistant to flow attemperatures as high as 350° C. and readily releases from the mold.

An important property of the thermoset polymer, which gives rise tothese desirable characteristics, is the extent to which the polymer iscrosslinked. An indication of the extent of crosslinking is provided bythe polymer's swell value. Gel and swell are determined by a modifiedversion of ASTM D-3616. The measurement is made after the polymer isimmersed in toluene for two hours at 100° C. Percent swell is defined asswollen polymer weight minus initial polymer weight, divided by initialpolymer weight times one hundred. It has been found that the polymerizedcycloolefins of this invention have a swell value of less than about twohundred percent. Preferably, the polymerized cycloolefins of theinvention have a swell value less than 150 percent. More preferably, thepolymer products of the invention have a swell value of less than 100percent. Preferably, the percent gel is at least 85% by weight ofpolymerization feed mixture. More preferably, the percent gel is atleast 90%. Most preferably, the percent gel is at least 95% by weight.

Billmeyer in the Textbook of Polymer Science (1962) at page 52 disclosesthat a crosslinked polymer cannot dissolve completely but may swell tomany times its original volume by absorbing a liquid with which it is incontact. Swelling occurs for the same reason that a linear polymerdissolves; the addition of solvent affords an increase in entropy. Theswollen gel is in fact an elastic rather than a viscous solution. Thetendency towards swelling is opposed by an elastic retractive forcearising as the chains between network junctions are forced to assumeelongated confirmations. The swelling of the gel in pure solvent may beused to measure the second virial coefficient of the crosslinked polymerin that solvent. The change in volume measures the change in activity ofthe solution and thus, the number-average molecular weight of thepolymer. Treloar in the Physics of Rubber Elasticity (1975) at pages142-145 discloses a relation between swelling and modulus. A relation isexpressed between the equilibrium swelling and the degree ofcrosslinking represented in terms of the molecular weight of the networkchains.

Various additives can be included to modify the properties ofcycloolefin polymer product of the invention. Possible additives includefillers, pigments, antioxidants, light stabilizers, plasticizers andpolymeric modifiers. The disclosure of U.S. Pat. No. 4,436,858 isincorporated herein by reference. Because of the rapid polymerizationtime the additives must be incorporated before the cycloolefin monomersets up in the mold. It is often desirable that the additives becombined with one or both of the catalyst system's streams before beinginjected into the mold. Reinforcing materials can also be charged to themold cavity, prior to charging the reaction streams, if the fillers aresuch that the reaction stream can readily flow around them to fill theremaining void space in the mold. It is essential that the additives notadversely affect catalytic activity.

One class of possible additives is reinforcing agents or fillers. Theseare compounds which can increase the polymer's flexural modulus withonly a small sacrifice in impact resistance. Possible fillers includeglass, wollastonite, mica, carbon black, talc, and calcium carbonate. Itis surprising that, in spite of the highly polar nature of the surfacesof some of these fillers, they can be added without appreciablyadversely affecting the polymerization rate. From about 0% to 75% byweight of additives can be incorporated. Preferably from 1 to 40% byweight of additives are incorporated. This and all subsequentpercentages are based on the weight of the final product. The additionof fillers which have modified surface properties are particularlyadvantageous. The exact amount of a particular filler to be used in aparticular situation will be easily determinable and will depend on thepreferences of the practitioner. The addition of fillers also serves todecrease the mold shrinkage of the product. After a short post cure at150°-200° C. an unfilled product will shrink from about 3.0 to about3.5% whereas adding 20-25 wt% filler will decrease the shrinkage to1.5-2% and adding 33 wt% filler will further decrease shrinkage to about1%.

Where the filler includes fine particles of a material which issubstantially chemically inert to the polymerization of the cycloolefin,this material is believed to act as a heat sink. It thus absorbs theexothermic heat of polymerization. In the presence of an effectiveamount (for example 10% by weight, of evenly distributed 1/16 inch longmilled glass fibers or wollastonite particles) of chemically inert heatsink material the maximum temperature of polymerization is lowered. Thisis believed to extend the active life of the catalyst so that less thantwo percent residual monomer is left in the cycloolefin polymer product.Preferably, the quantity, distribution and fineness of the chemicallyinert heat sink material is effective to result in less than one percentresidual monomer in a commercial polymerization. More preferably thequantity, distribution and fineness of the chemically inert heat sinkmaterial is effective to result in order of increasing preference inless than 0.9, 0.8, 0.5, 0.3 or 0.05 percent residual monomer in acommercial polymerization. Most preferably the quantity, distributionand fineness of the chemically inert heat sink material is effective toresult in less than 0.1 percent residual monomer in a commercialpolymerization.

Similarly, low residual monomer polymer products are obtained bycontrolled reaction of cycloolefin monomer using tungsten compoundcatalyst and dialkylaluminum chloride activator in an activator tocatalyst ratio within the range of from about 2.5:1 to about 6:1. Morepreferably, the activator to catalyst ratio is from 2.5:1 to about 4:1.Most preferably, the activator to catalyst ratio is from about 3:1 toabout 3.5:1 to obtain a polymer product having from about 0.3 to about1.5 percent by weight residual monomer.

Flame retardant additives may be added to one or more of the monomerfeed streams to form polymers which are resistant to burning. Forexample, on a weight basis a flame retardant mixture of 17 parts ofN,N'-ethylene-bis-tetrabromophthalimide, 7 parts Sb₂ O₃ and 8 parts NH₄BF₄ as the flame retardant mixture per 100 parts of dicyclopentadieneimparts a V-0 rating in the UL-94V burn test where UL is an abbreviationfor Underwriters Laboratories when mixed with 0.05 parts WCl₆ and 0.15parts of tri-n-octyl aluminum as described herein to form substantiallycrosslinked polymerized units of dicyclopentadiene. This representseffective flame retardation. The range of weight portions for effectiveflame retardation is from 8 to 20 parts ofN,N'-ethylene-bis-tetrabromophthalimide, from 6 to 15 parts NH₄ BF₄ andfrom 3 to 11 parts Sb₂ O₃ per 100 parts of dicyclopentadiene.

The polymers formed in accordance with the present invention includefoams. Foaming is carried out by including a blowing agent as describedin U.S. patent application Ser. No. 526,836, (Newburg) the disclosure ofwhich is incorporated by reference.

Since polymerized dicyclopentadiene contains some carbon-carbonunsaturation it may be subject to oxidation. The product can beprotected by the incorporation of as much as about 2.0 wt% of a phenolicor amine antioxidant. Preferred antioxidants include2,6-di-tert-butyl-p-cresol, N,N'-diphenyl-p-phenylene diamine andtetrakis [methylene(3,5-di-t-butyl-4-hydroxy cinnamate)] methane. Whilethe antioxidant can be added to either or both streams, incorporationinto the catalyst/monomer stream is preferred.

A supramolecular IPN is believed to be formed in the embodiments of thepresent invention in which styrene butadiene rubber is present duringthe polymerization of dicyclopentadiene as described hereinafter. Theaddition of an elastomer can increase the polymer's impact strength 5-10fold with only a slight decrease in flexural modulus. The elastomer canbe dissolved in either or both of the DCPD streams in the 5-10 wt% rangewithout causing an excessive increase in the solution viscosity. Usefulelastomers may be unsaturated such as styrene-butadiene rubber,polyisoprene, polybutadiene, natural rubber, styrene-isoprene-styrenetriblock rubber, styrene-butadiene-styrene triblock rubber, andethylene-propylene diene terpolymers; or saturated such aspolyisobutylene and ethylene-propylene copolymer. It is believed that asaturated elastomer forms a semi-interpenetrating network when presentduring the polymerization of a cycloolefin, such as dicyclopentadiene.Each of the unsaturated elastomers is believed to form aninterpenetrating network with the polymerized units of cycloolefin, suchas dicyclopentadiene, when present during the polymerization of themonomer. The amount of elastomer used is determined by its molecularweight and is limited by the viscosity of the streams. The streamscannot be so viscous that adequate mixing is not possible. TheBrookfield viscosity of dicyclopentadiene is about 6 cps at 35° C.Increasing the viscosity to between about 300 cps and about 1000 cpsimproves the mold filling characteristics of the combined streams. Anincrease in viscosity reduces leakage from the mold and simplifies theuse of fillers by decreasing the settling rates of the solids. Anexample of a preferred polymerization. Where 6 wt% of this additive isincorporated into the streams not only is the viscosity increased toabout 300 cps but the impact strength of the final product alsoincreases. Although the elastomer can be dissolved in either one or bothof the streams it is desirable that it be dissolved in both. When thetwo streams have similar viscosities more uniform mixing is obtained.

Monomer Preparation

Preferred monomers are cycloolefins of the norbornene-type and are thosedefined by the following formulas: ##STR7## where R and R¹ areindependently selected from hydrogen, alkyl groups of 1 to 20 carbonatoms, and saturated and unsaturated hydrocarbon cyclic groups formed byR and R¹ together with the two ring carbon atoms. R² and R³ areindependently selected from hydrogen and alkyl groups containing 1 to 20carbon atoms.

Dicyclopentadiene (DCPD) for use in forming substantially crosslinkedthermoset polymers which may be formed for example in reaction injectionmolding (RIM) is required because of high purity. The degree of purityof the DCPD monomer may determine whether the polymerization proceeds atall and whether an acceptable polymer is formed if polymerizationoccurs.

The highest purity commercial grade of monomer, 97% by weightdicyclopentadiene, is unacceptable for polymerization withoutpurification. Ninety-seven percent by weight dicyclopentadiene can bemade acceptable for RIM use by distillation. For example, a columnpacked with 1-inch Intalox Saddles (10-12 theoretical trays) providesdicyclopentadiene purification with recovery of purifieddicyclopentadiene of about 70-75% because the relative volatilities ofsome of the polymerization inhibitors appear to be very close to that ofdicyclopentadiene. Purified dicyclopentadiene substantially completelypolymerizes in about 3/4 minute or less. Purified dicyclopentadiene isproduced by nitrogen sparging 97% by weight dicyclopentadiene followedby treatment with alumina.

Although polymerization inhibitors in crude dicyclopentadiene are stillnot fully identified, suspected contaminants are polar compounds such asepoxides, alcohols, aldehydes, and some other oxygen-containingcompounds. Oxygenated compounds have generally intermediate or highpolarity and are adsorbed on alumina or in zeolites.

The major volatile impurities in the 97% pure commercialdicyclopentadiene are isoprene and cis/trans 1,3-pentadiene, which donot affect the polymerization, but are undesirable for a reactioninjection molding process. The volatile compounds can be removed simplyby stripping.

Adsorption, in both mixing contact and fixed bed (percolation), areused. The contact method consists of mixing the dicyclopentadiene to bepurified with an adsorbent in a container with inert atmosphere undercontrolled time and temperature conditions. Agitation is accomplished byadding a magnetic stirring bar to the container. In the fixed bedmethod, the DCPD is purified by passing it through a column packed withan adsorbent under controlled flow and temperature conditions.

One of the most effective adsorbent for DCPD purifications is Linde 10 Amolecular sieve (Union Carbide Type 13X M.S.). This adsorbent rapidlyturns to a dark chocolate brown color when 97% by weightdicyclopentadiene is added. Most of the dark color can be extracted fromthe molecular sieves by acetone or hexane. IR analyses indicated thatthe color extracts are consisted mainly of oxygenated compounds and someunsaturated cis-olefin. Activated alumina is also effective in removingcatalysis poisons from dicyclopentadiene.

A series of mixing tests are conducted to compare the effectiveness ofvarious adsorbents. The results are shown in Table I.

                  TABLE I                                                         ______________________________________                                                        Polymerization delay                                                          time in seconds                                               ______________________________________                                        Alumina           53-65                                                       Zeolite (8-9 A pour size)                                                                       84                                                          (4-5 A pour size) 85                                                          Linde Mole Sieve, 4 A                                                                           98                                                          5 A               65                                                          ED-3100           55                                                          10 A              40                                                          ______________________________________                                    

Polymerization delay time is measured after 90 minutes of mixing. DCPDused for mixing is 4% topped 97% by weight DCPD (delay time--2.5minutes).

Percolation Tests and Mileage

Dicyclopentadiene is purified by passing it through a 1-indiameter×4-ft. column packed with various adsorbents. The column ismaintained at 50° C. and fed either downward or upward direction bygravity. Feeding upward reduces the number and size of bubbles trappedin the column. Crude DCPD is fed to the packed bed by N₂ pressure from a5-gallon bomb placed on top of the column. Samples of feed and effluentare analyzed for delay time (induction time) and the exotherm generated,for every 30-45 minute to monitor the performance of adsorbents.

Alumina is selected for percolation. In order to minimize the amount ofmoisture adsorbed, alumina is dried in a 150°-200° C. oven before usage.Alumina beds are also run in series with a Linde 13X mole sieve column.Both mixing and percolation indicate that 13X mole sieve is moreeffective in reducing the delay time than alumina.

In order to achieve the delay time of 1 minute or less after adsorption,the delay time of feed is approximately 2-3 minutes.

The capacity or mileage (ratio of volume purified DCPD to adsorbent bedvolume) of alumina depends on the impurity content of the DCPD feed. Amileage of about 80 is expected when DCPD is purified from the delaytime of about 2 minutes to 1 minute or less.

A flow rate of 20 ml/min (0.24 gpm/ft³ packing or residence time ofapproximately 15 minutes) is adequate. A residence time of less thanabout 10 minutes sharply increases the delay time of the columneffluent. Longer contacting times than 15 minutes improve the purity ofthe effluent, especially when the DCPD feed has a high delay time or ifsome of packed alumina is exhausted.

At a constant throughput, the adsorption capacity is a function of thebed length. For various throughputs or flow rates with a constant bedlength, slower flow rate gives higher adsorption capacity. At 20 ml/minflow rate, the estimated residence time is about 15 minutes (packingvolume approximately 600 ml).

Preferably 13X molecular sieve is used as a finishing adsorbent byrunning alumina and 13X molecular sieve columns in series. The color ofalumina is gradually darkened from the feed end as the bed gets old.Color developed in the column gives the column effluent a yellowishtint.

Calcination and Regeneration

Alumina is regenerated by purging with dry gas at 225° C. after dryingapplications. The adsorbent is regenerated to almost the initialactivity by burning off the deposits at temperatures between 500°-600°C. However, applying temperature above 700° C. would adversely affectthe activity.

Effects of regeneration temperature on the activity of alumina are shownby checking the delay time of DCPD treated with regenerated alumina atvarious temperatures. Spent alumina was placed in a temperaturecontrolled oven (250°-650° C.) for one hour. Analyses of spent aluminaand 13X mole sieve over temperature range of 300°-600° C. show thatregeneration might be completed in 30-60 minutes. Organic residues inspent alumina do not burn off completely at 400° C. or below.Regeneration at 500°-600° C. changed dark shaded spent alumina back tothe original white color.

Spent alumina regenerated at 500°-600° C. consistently outperforms freshalumina dried at 150°-200° C. The findings led to investigation of theeffects of calcining (drying at high temperature) on the activity offresh alumina.

Fresh aluminas are calcined at 250°-650° C. and activities compared. Theresults show that the activities of calcined alumina gradually improveas the calcination temperature increases. The delay time of 10% topped97% dicyclopentadiene is reduced from 2.0-2.5 minutes to 53 secondsafter mixing with alumina dried at 250° C., but was further improved tobelow 35 seconds when the alumina was calcined at 650° C.

The activities of both calcined and regenerated alumina at 600°-650° C.are similar. The mileages of both calcined and once regenerated aluminaat 600° C. are equivalent to fresh alumina dried at 150°-200° C.

When either the calcined or regenerated alumina is used as an adsorbent,purified dicyclopentadiene picks up greenish-yellow color. The coloredmaterial is concentrated in the pot of a laboratory batch distillationcolumn when a colored effluent of the adsorption column is fractionatedand purified dicyclopentadiene is removed from the overhead gradually.The results demonstrate that these colored compounds are high boilingimpurities and are separated from purified dicyclopentadiene bydistillation.

Distillation and Adsorption

The polymerization of distillation cuts indicates that 95% by weightdicyclopentadiene can be sufficiently purified by distillation for usein RIM. Distillation fractions of the lower purity dicyclopentadiene donot react well at normal catalyst levels, and the highest degree ofpolymerization achieved is a gel.

As shown in Table 2, the recovery of purified monomer is substantiallyimproved by adsorption after distillation.

                  TABLE 2                                                         ______________________________________                                                  Yields, %.sup.(a)                                                             Distillation                                                                          Distillation/Adsorption                                     ______________________________________                                        97% DCPD    80        90                                                      95% DCPD    40-65     80-85                                                   ______________________________________                                         .sup.(a) Assuming 1 minute or less delay time is acceptable for purified      monomer. Calcined alumina is used as an adsorbent.                       

Spent alumina could be regenerated by heating to 500°-600° C. for 30minutes. Performance of regenerated alumina appears to be equivalent tofresh alumina dried at 500°-600° C. The activity of fresh alumina couldbe substantially improved by calcinating at 500°-600° C.

Laboratory adsorption column tests showed that flow rates of 0.20-0.25gpm/ft³ packing, which give approximately 15 minutes residence time, areadequate. Slower flow rates would improve the efficiency, especiallywhen much of the adsorbents are exhausted, but the improvements areminor.

Pure dicyclopentadiene (99.9+% by weight DCPD) is a crystalline solidhaving a melting point of 34° C. (90° F.) and a flash point of about103° F. To be useful for spontaneous polymerization to formsubstantially crosslinked polymerized units of dicyclopentadiene, thepolymerization mixture must be a liquid. To avoid a fire hazard theliquid polymerization mixture preferably has a flash point of 100° F. orhigher. The most pure, commercially available, dicyclopentadiene is 97%dicyclopentadiene having a viscosity of about 3.5 centipoises (cps) anda flash point of about 80° F. A significant portion of the about 3%which is not DCPD is low boiling hydrocarbonaceous compounds, such as C₁to C₄ alkane, alkene, aromatic and substituted aromatic compounds. Thesehydrocarbonaceous compounds are effective to prevent crystal formation.The viscosity is preferably raised by addition of elastomer as discussedherein. The flash point can be raised by addition of high boilinghydrocarbonaceous compounds, such as C₅ -C₂₀ alkanes, alkenes andaromatic compounds.

Avoiding suppression of the flash point is also important. High boilingsubstituents may be used for the activator. Preferably, the alkyl groupsof the alkyl aluminum activator have from 5 to 10 carbon atoms.

Monomer Character

The cycloolefin monomer preferably has a flash point of 100° F. orhigher and a viscosity of from about 3 cps. to about 5 cps. withaddition of materials such as elastomer which increase viscosity, thepreferred range of viscosity is from bout 3 cps. to about 3000. For RIM,the more preferred viscosity range is from about 100 to about 1000 cps.Lower flash points make storage and handling expensive and complex dueto fire prevention requirements.

In some in-mold polymerization processes, low viscosity monomer isadvantageous, such as pour molding of detailed shapes. While in otherpolymerization processes, higher viscosity monomer is needed such as inreaction injection molding. High purity monomer is needed for fastpolymerization of cycloolefin, such as dicyclopentadiene. However, atpurities of about 99.8 and above, at 70° F. dicyclopentadiene issubstantially nonfluid (i.e., a solid). At purities below 95 percent,the rate of polymerization is significantly reduced.

A preferred example of a a high flash point cycloolefin composition,includes a cycloolefin mixture. The cycloolefin mixture includes atleast 80% by weight dicyclopentadiene. This composition has a flashpoint of greater than 100° F. and a viscosity of from about 3 cps toabout 1000 cps at about 70° F. and about 1 atmosphere pressure. Apreferred reactant solution is comprised of dicyclopentadiene;trialkylaluminum, where each alkyl contains from 5 to 10 carbon atomswhere the trialkylaluminum is present in a dicyclopentadiene totrialkylaluminum molar ratio of about 80:1 to about 1300:1; andbis(2-methoxyethyl)ether, where the bis(2-methoxyethyl) ether is presentin a trialkylaluminum to bis(2-methoxyethyl) ether molar ratio of atleast 1:0.5.

A halogen-free reactant solution is comprised of dicyclopentadiene(hereinafter referred to as DCPD), trialkylaluminum andbis(2-methoxyethyl) ether. In the preferred embodiment of the reactantsolution, dicyclopentadiene is the only monomer present. In otherembodiments, the reactant solution may additionally contain up to about20% of one or more other metathesis polymerizable, cycloolefincomonomers, so long as the comonomer does not lower the flash point ofthe reactant solution below 100° F. Representative cycloolefincomonomers include norbornene, norbornadiene,dimethanohexahydronaphthalene, and dimethanooctahydronaphthalene. Theflash point of any particular combination of monomers is readilydeterminable without undue experimentation by employing the method ofASTM D3278.

The reactant solution also contains trialkylaluminum. Each alkyl iscomposed of from 5 to 10 carbon atoms and each alkyl can be straightchained or branched. The preferred trialkylaluminum is tri-n-octylaluminum. The trialkylaluminum is present in a dicyclopentadiene totrialkylaluminum molar ratio of about 80:1 to about 1300:1, preferablyabout 200:1 to about 500:1.

The third component of the reactant solution is bis(2-methoxyethyl)ether. The molar ratio of the trialkylaluminum to bis(2-methoxyethyl)ether is at least about 1:0.5, preferably about 1:1 to about 1:4. Formaximum effectiveness as a reactant solution in the method described inU.S. Pat. No. 4,400,340, the bis(2-methoxyethyl) ether is added to themonomer or combination of monomers before the trialkylaluminum is added.

In some embodiments, a preformed elastomer is added to the reactantsolution. The addition of the elastomer serves to increase the viscosityof the reactant solution and improve the impact resistance of a finalthermoset polymeric product produced in accordance with the methoddisclosed in U.S. Pat. No. 4,400,340. The elastomer is dissolved in anamount of from about 3 to about 15 weight percent, based on the weightof the monomer or combination of monomers. Illustrative elastomersinclude natural rubber, butyl rubber, polyisoprene, polybutadiene,polyisobutylene, ethylene-propylene copolymer, styrene-butadiene-styrenetriblock rubber, random styrene-butadiene rubber,styrene-isoprene-styrene triblock rubber, and ethylene-propylenedieneterpolymers.

Preferably, the high flash point dicyclopentadiene composition of theinvention includes at least 50 percent by weight DCPD and morepreferably 80 percent by weight dicyclopentadiene and has a flash pointof greater than 100° F. Most preferably, the high flash pointdicyclopentadiene composition of the invention includes at least 95percent by weight dicyclopentadiene and has a flash point of more than100° F.

The best mode now contemplated of carrying out this invention isexemplified by the following working examples of preferred specificembodiments. The invention is not limited to these specific examples.

EXAMPLES

Examples A-E illustrate preferred embodiments of reactant solutionscomprised of DCPD, tri-n-octylaluminum (TNOCTAL) andbis(2-methoxyethyl)ether (diglyme).

Reactant solutions are made in the following manner: first, diglyme isadded to dicyclopentadiene. Next, TNOCTAL is added to the diglyme-DCPDsolution. The amount of each component is shown in Table A.

The flash point of each sample was actually measured by the method ofASTM D-3278 using a Seta flash closed tester (manufactured by Paul N.Gardner Co., Lauderdale by the Sea, Fla.). The flash point of eachsample is shown in Table 2A.

                                      TABLE 2A                                    __________________________________________________________________________           Example A                                                                            Example B                                                                            Example C                                                                            Example D                                                                            Example E                                  __________________________________________________________________________    DCPD   368                                                                              mmol                                                                              379                                                                              mmol                                                                              366                                                                              mmol                                                                              368                                                                              mmol                                                                              364                                                                              mmol                                    TNOCTAL                                                                              1.1                                                                              mmol                                                                              1.1                                                                              mmol                                                                              1.3                                                                              mmol                                                                              1.9                                                                              mmol                                                                              4.7                                                                              mmol                                    diglyme                                                                              4.4                                                                              mmol                                                                              21 mmol                                                                              1.3                                                                              mmol                                                                              1.9                                                                              mmol                                                                              4.7                                                                              mmol                                    Flash  102° F.                                                                       105° F.                                                                       104° F.                                                                       105° F.                                                                       105° F.                             point                                                                         __________________________________________________________________________

Catalyst Preparation

The novel catalyst composition preferred for polymerization ofcycloolefin preferably of norbornene-type monomers includes WCl₄ O andWCl₆ in a molar ratio of WCl₄ O to WCl₆ of from about 1:9 to 2:1 (i.e.,about 10-67% WOCl₄) to about 90-33% WCl₆. A novel method of making thecatalyst precursor material is provided, the major portion of which isWCl₆. The catalyst precursor is then contacted with controlledproportions of the oxygen donor. WCl₆ reacts with oxygen donor to formWCl₄ O in a molar ratio of WCl₄ O to WCl₆ of between about 1:9 and 2:1.

The percentage increase of catalyst activity as determined by thedecrease in the amount of catalyst needed to successfully polymerizemonomer to a residual monomer level of 1% or less is from 100%-1000%.The polymerized cycloolefin products of the present invention haveresidual monomer of less than 2 percent. Preferably these products haveless than 1.0 percent residual monomer. More preferably the polymerproducts of the invention contain less than 0.8 percent residualmonomer. Most preferably, the polymerized polyolefin products of theinvention contain less than 0.5 percent residual monomer. As theproportion of residual monomer decreases, the properties of the productimprove. For example, the flexural modulus increases and latent odordecreases to be lower than perceptible by smell for most human beings atamounts less than 1 percent. Preferably, the catalyst composition isfrom about 10 to 75% WCl₄ O and is from about 25 to 90 percent WCl₆ ;Most preferably the catalyst composition is from about 25 to 50 percentWCl₄ O and from 50 to 75 percent WCl₆. The method provides controlledoxygen addition through reaction with a limited proportion of oxygensupplied by a source of oxygen, such as a hydrated salt, water, wetmolecular sieves, or an alcohol. For example, WCl₆ is rapidly convertedto WOCl₄ by treatment with a number of oxygen-containing materials,including H₂ O, alkyl alcohols, Cl₃ CNO₂ and CH₃ OSi(CH₃)₃. A preferredalkyl alcohol is t-butanol.

In a preferred embodiment a gaseous mixture of carrier gas such asnitrogen and water vapor is added to a stirred mixture of catalystprecursor (for example WCl₆) in solvent such as toluene under an inertatmosphere. The gaseous mixture of carrier gas and water vapor iscarried to a point beneath or slightly above the solvent surface in themixing vessel from a container of the solvent and water into which isintroduced dry carrier gas. By proportioning the amount of water to theamount of catalyst precursor, oxygen addition from the water to thecatalyst precursor to form the product is controlled. The amount ofwater initially in the feed container is in proportion to the amount ofcatalyst precursor in the mixing vessel. The generalized reaction I isbelieved to take place as follows:

    H.sub.2 O+WCl.sub.6 WOCl.sub.4 +2HCl                       (I);

The molar ratio of water to catalyst precursor is preferably from 0.25to 0.75. The inactivation of catalyst product may occur if overexposureto oxygen-donor material is permitted. Oxidation products which areinactive for cycloolefin polymerization are WO₂ Cl₂ and WO₃. Thereaction is complicated by the fact that WOCl₄, while more stable thanWCl₆, is still susceptible to hydrolysis as shown in reactions II:

    ______________________________________                                        (II)      WCl.sub.6 + H.sub.2 O                                                                        WOCl.sub.4 + 2HCl                                              WOCl.sub.4 + H.sub.2 O                                                                       WO.sub.2 Cl.sub.2 + 2HCl                                       WO.sub.2 Cl.sub.2 + H.sub.2 O                                                                WO.sub.3 + 2HCl                                      ______________________________________                                    

Therefore, it is necessary to carefully control the reaction to minimizethe formation of these byproducts.

WCl₄ O catalyst is prepared by controlled addition of water. This isreadily accomplished either by sparging a WCl₆ solution with wet N₂ gasor by adding a hydrated inorganic salt, such as FeSO₄.7H₂ O. Thepreferred proportion of water is about 0.5 mole per mole tungsten.Phenol and acetylacetone (acac) are added to solubilize and stabilizerespectively the system in cycloolefin. Catalyst prepared in thisfashion is effective in polymerization of cycloolefins such as DCPD at acycloolefin to catalyst ratio of as low as 14000:1.

Alcohols such as methanol and isopropanol and CH₃ OSi (CH₃)₃ give slightimprovements in catalyst activity. This may be due to formation ofbyproducts. In the controlled hydrolysis of WCl₆ wet nitrogen gas issparged through a 0.1M toluene solution of WCl₆ until a known amount ofwater is added. The appropriate volume of water is premixed with tolueneso that the gas is also saturated with toluene vapor. During theaddition, a small amount of the precipitate forms and the blue-purplesolution gains a very faint reddish tint. After the addition of water iscomplete, one equivalent each of phenol and acetylacetone (acac) areadded to give the catalyst.

The second embodiment of the catalyst preparation method uses hydratedinorganic salts as water carriers. FeSO₄.7H₂ O is crushed to a powder.The WCl₆ solution is then added and the mixture is allowed to stir foran hour. The solution is then decanted away from the salt. Phenol andacetylacetone (acac) are added as above.

In a alternative preparation of catalyst, very pure WCl₆ is treated withtert-butanol. Tert-butanol dissociates to form water and iso-butylene.Thus, t-butanol serves as a water source in the same way that hydratedsalts or molecular sieves might. Addition of t-butanol to a suspensionof WCl₆ in an organic solvent such as toluene or xylene greatlyincreases the activity of the catalyst. In order to prepare catalystsuitable for RIM processing, nonylphenol and acac are added as disclosedin U.S. Pat. No. 4,400,340. The molar ratio of t-butanol to tungsten ispreferably from 0.10 to 0.75, most preferably from 0.25 to 0.50.

Unlike the case of water vapor, where the oxygen source can be added tothe catalyst before or after addition of the phenol, with t-butanol itis preferred to add t-butanol before the phenol.

A preferred polymerization catalyst composition includes a mixture of acompound of the general formula: ##STR8## wherein R is an alkyl grouphaving 3 to 20 carbon atoms; m is 4 or 6 and n is 1 or 0. Thepolymerization catalyst preferably further includes a compound of thegeneral formula: ##STR9## wherein R₁ and R₂ are independently hydrogenor an alkyl group of from 1 to 5 carbons. In compositions more preferredn is 1; m is 4 and R is nonyl. Most preferably the polymerizationcatalyst composition further includes compound selected from the groupconsisting of of 2,4-pentanedione and diglyme. A most preferredpolymerization catalyst composition is a compound of the general formula##STR10## wherein R is an alkyl group of from 1 to 20 carbon atoms; Ris₁ hydrogen or an alkyl group of from 1 to 5 carbon atoms; R₂ ishydrogen or an alkyl group of from 1 to 5 carbon atoms; R₃ is hydrogenor an alkyl group of from 1 to 5 carbon atoms; R₄ is hydrogen or analkyl group of from 1 to 5 carbon atoms.

Noncycloolefin Solvent-Free Catalyst Solution

A catalyst solution of WCl₆ and WCl₄ O in a 1:1 molar ratio in phenoland acac is preferred as described above. The catalyst solution of WCl₆and WCl₄ O in toluene is added to the DCPD and warmed at 35° C. for 24hours to vaporize the toluene. The resulting solution is substantiallyfree of toluene and other noncycloolefin solvents for the WCl₆ --WCl₄ Ocatalyst. That is, other than cycloolefins there is substantially nosolvent present.

One of the advantages of the reaction injection molding (RIM) process isthat since the reactive streams are initially low viscosity liquids itshould be especially suited for molding large or intricately shapedparts. The prior art however does not teach any method to control orprevent the occurrence of gellation prior to the substantially completeconversion of monomer into polymer. Gellation of the monomer ischaracterized by a sharp increase in the viscosity of the monomer,generally to greater than 100,000 centipoise, at some time prior to thesubstantially complete conversion of monomer into polymer.

Two Part Activator Embodiment

An improved method of the invention is for making a thermoset polymer ofcyclic olefins, for example, dicyclopentadiene. Dicyclopentadienemonomer is polymerized with a three component olefin metathesis catalystsystem whereby the length of the gel time relative to the cure time canbe controlled by the proportions of the catalyst system components. Inthis way, the gel time is made to coincide with the cure time withoutaffecting any of the other properties of the polymer. The catalystsystem is made up of a two part activator and a catalyst which is amonomer soluble or solvent soluble tungsten compound. The two partactivator includes a trialkylaluminum compound or a dialkylaluminumchloride, as the first part of the activator, and a dialkylaluminumiodide as the second part of the activator. In a preferred embodiment,the three parts of the olefin metathesis catalyst, plus the monomer,form the basis of at least two separate reactive streams. These can bemixed in one place, such as the mixing head of a reaction injectionmolding machine, and then injected into a mold where they will set upinto a solid insoluble cross-linked polymer. By varying the ratio of theactivator to catalyst, the gel time, as a fraction of the total curetime, can be varied from approximately 35% of the cure time to 100% ofthe cure time. To so vary the gel time the ratio of activator tocatalyst is varied from 3:1 to 2.4:1 on a molar basis.

U.S. Pat. No. 4,458,037 (Leach 1) incorporated herein by referencediscloses an improved process for making a cellular crosslinkedpolymerized dicyclopentadiene with an olefin metathesis catalyst system.An improvement of the Leach process is the use of dialkylaluminumiodides such as diethylaluminum iodide as catalyst activators. (The useof a two component olefin metathesis catalyst consisting of a tungstenoxyhalide or halide such as tungsten hexachloride and a dialkylaluminumiodide for the polymerization of dicyclopentadiene results in apolymerization which does not exhibit gellation due to crosslinking,prior to the exothermic polymerization and thus can be expanded to auniform cellular polymer.) The use of other aluminum alkyls such astrialkylaluminums or dialkylaluminum chlorides is found to beunsatisfactory for foam formation and mold filling. Their use with atungsten catalyst such as tungsten hexachloride results in the earlyformation of a gelled crosslinked network. Such networks in generalcannot be expanded uniformly.

In a preferred embodiment composition and method of making a cellularcrosslinked polymerized dicyclopentadiene provides dicyclopentadiene(DCPD) monomer which is polymerized with an olefin metathesis catalystsystem discussed above, this improved process provides uniform cellularpolymers of cyclic olefins such as dicyclopentadiene, these polymershave a substantially crosslinked structure and improved physicalproperties. In a preferred embodiment, the three part olefin metathesiscatalyst (catalyst and two part activator), and the monomer and ablowing agent form the basis of at least two separate reactant streams.These reactant streams can be mixed in one place, such as the mixingchamber of a reaction injection molding machine, and then injected intoanother place such as a mold, where the monomer polymerizes to acellular crosslinked polymer. The addition of a surfactant or foamstabilizing agent to the monomer mixture results in the formation of acellular polymer where the bubbles are much smaller and of a moreuniform size. Also a higher percentage of the bubbles in the cellularpolymer are closed when a surfactant has been added.

By deleting the blowing agent intricate molds are readily filled usingthe combined reactant streams. The resulting product is an intricatelyshaped noncellular polymer. Molding may be by pour molding, spraymolding, RIM, etc.

The polymerization of the dicyclopentadiene monomer is preferablycatalyzed by the three part metathesis catalyst system. Catalyst isdissolved in one reactive stream while the two part activator is addedto a second monomer stream.

Use of a three component olefin metathesis catalyst as described abovecontaining a trialkylaluminum compound or a dialkylaluminum chloride andonly a small amount of dialkylaluminum iodide relative to either of theother two components results in a polymerization which also does notexhibit gellation due to crosslinking and thus can be used to produceuniform cellular polymers. In addition, polymers produced by thisprocess form a more highly crosslinked structure after their expansionto a cellular polymer than the polymers of the invention of U.S. Pat.No. 4,458,037 (Leach 1), and thus have more desirable end propertiessuch as creep resistance and compressive strength. Low density foams canbe made using the composition and method of the present invention.

The first part of the activator is composed of a trialkylaluminumcompound or dialkylaluminum chloride where each alkyl group containsfrom one to twelve carbon atoms. Preferred dialkylaluminum chlorides arediethyl aluminum chloride and dioctylaluminum chloride. A preferredtrialkylaluminum compound is trioctylaluminum.

The second part of the activator is composed of a dialkylaluminumdiodide where each alkyl group contains from one to twelve carbon atoms.Preferred dialkylaluminum iodides include diethylaluminum iodide anddioctylaluminum iodide. Dioctylaluminum iodide is preferred.

Blowing Agent

A blowing agent is incorporated into the reactive streams in order thata product having a cellular structure is formed during polymerization.Any of the conventional blowing agents used in reaction injectionmolding processes or related processes may be employed provided that theblowing agent does not poison or otherwise adversely affect themetathesis catalyst. Preferred blowing agents include low boilingorganic compounds, i.e. compounds which are liquids under ambientconditions but which are volatilized under polymerization conditions,and inert gasses. Representative low boiling organic compounds includehydrocarbons such as pentane and hexane, and halogenated hydrocarbonssuch as methylene chloride, trichlorofluoromethane and1,1,2-trichloro-1,2,2-trifluoroethane. Representative inert gassesinclude nitrogen, argon and fluorinated hydrocarbons, such asdichlorodifluoromethane and 1,2-dichloro-1,1,2,2-tetrafluoroethane.

The blowing agent is incorporated into either or both reactive streams,or it may be added to a separate monomer stream. The amount of blowingagent to be incorporated is from about 2 to about 30, preferably fromabout 4 to about 20, percent by weight based on the weight of themonomer. The greater the amount of blowing agent used the less dense thefinal cellular crosslinked polymer produced.

In some embodiments, the cellular crosslinked polymer of this inventionis made and molded by RIM or related processes.

The two parts of the metathesis-catalyst system are separately mixedwith monomer and blowing agent to form two suitable solutions which areplaced in separate vessels. These vessels provide the source forseparate streams. The two streams are combined in one place, such as aRIM machine's mixing head, and then injected into a second place, suchas a mold where polymerization takes place.

The invention is not intended to be limited to embodiments employing twostreams each containing monomer and blowing agent. It will be obvious toone skilled in the art that there may be situations where it isdesirable to have monomer incorporated in just one stream or to employ aplurality of streams where the additional streams contain monomer oradditives or both.

Bubble Stabilization

In some embodiments, a foam stabilizing agent such as a surfactant isadded to make the bubbles smaller and more uniform in size. Thisgenerally also results in the formation of foams in which a higherpercentage of the cells are closed than in embodiments which do notcontain a foam stabilizing agent. Having the bubbles small and ofuniform size generally results in improved properties such as flexmodulus, impact resistance and compressive strength for the foam. Havinga higher amount of closed cells is generally preferred for a number ofapplications such as insulation.

The use of surfactants as foam stabilizers is well known in thepreparation of polyurethane foams to produce foams with well dispersedsmall bubbles of uniform size. Surfactants commonly used forpolyurethanes are composed of graft or block copolymers of polysiliconesand polyethers such as polypropylene oxide or polyethylene oxide.Examples of such surfactants include silicone surfactants such asL-5410, L5420, L-5430, L540, and L-5350 manufactured by Union CarbideCorporation. However, with polydicyclopentadiene, surfactants such asthese are ineffective. Other common surfactants such as glyceryldioleate, polyoxyethylated tert-octylphenol, polyethyleneglycol 300dilaurate, sodium n-octyl-sulfate, alkyltrimethylammonium salts,polysorbates, alkanolamides, and perfluoroalkylpolyethers are alsoineffective.

Surfactants that are effective are fluorinated alkyl methacrylatecopolymers. Examples of suitable commercially available surfactantsinclude FC-740 and FC-432, which are fluorinated alkyl methacrylatecopolymer surfactants sold by Minnesota Mining and ManufacturingCompany. Other similar surfactants composed of fluorinated copolymers ofalkyl methacrylates are also effective. The molecular weight of thepolymeric surfactant appears not to have an effect on its foamstabilizing ability so that the only limit on molecular weight would bethat it not be so high as to require large amounts of inert solvent as adiluent to make it easy to transfer, weight, or otherwise handle thesurfactant solution. In addition, the solvent that the surfactant isdissolved in should not interfere with or inhibit the polymerization.The amount of surfactant added should be from about 0.1% to about 1.0%of the amount of dicyclopentadiene monomer. The surfactant may be addedto either the catalyst and monomer stream or the activator and monomerstream. Since the surfactant causes the monomer streams to foam underagitation, and thus have a lower density, it is preferably added to bothstreams so that they will have the same density.

In some embodiments, a nucleating agent, such as calcium carbonate, isadded to at least one of the reactant streams. The nucleating agentaffects the structure of the foam by making the cells small and uniform.Other suitable nucleating agents include talc, magnesium carbonate,barium carbonate, zinc carbonate, lead carbonate, magnesium oxide,calcium oxide, polyethylene, and silica. The preferred nucleating agentis silica.

EXAMPLES 1 AND 2

In Example 1 a 0.1M solution of a tungsten containing catalyst solutionis prepared by adding 20 grams of WCl₆ in 60 ml of dry toluene under aN₂ atmosphere and then adding a solution of 8.2 grams of p-tert-butylphenol in 30 ml of toluene. The catalyst solution is sparged overnightwith nitrogen to remove the HCl generated by the reaction of WCl₆ withthe p-tert-butylphenol. In this and in all the following examples,phenol is used as a shorthand for p-tert-butylphenol and for simplicitythe solution is referred to as WCl₆ /phenol. Then a 0.033Mcatalyst/monomer solution is prepared by mixing under nitrogen 10 ml ofdicyclopentadiene, 0.07 ml of benzonitrile and 5 ml of the 0.1M catalystsolution. An activator/monomer solution is prepared by combining, undernitrogen, 8.6 ml of dicyclopentadiene, 0.1 ml of isopropyl ether and0.36 ml of 1.0M diethylaluminum chloride (Et₂ AlCl) in DCPD.

Polymerization is accomplished by adding 1.1 ml of the 0.033Mcatalyst/monomer solution to 8.9 ml of the activator/monomer solution.Both solutions are initially at 25° C. They are vigorously mixed. Aftera brief induction period a sharp exotherm is observed. A solid,insoluble polymer is formed. The time that elapses until rapidpolymerization begins and the total exotherm of the sample above thestarting temperature are shown in Table I.

In Example 2 the above procedure is repeated except that 0.36 ml of 1.0MEtAlCl₂ is used in place of Et₂ AlCl to prepare the activator solutionand the reaction is started at 40° C. A solid, insoluble polymer isformed. The results are shown in Table 3.

                  TABLE 3                                                         ______________________________________                                                      Example 1      Example 2                                        ______________________________________                                        DCPD            72     mmol      72   mmol                                    WCl.sub.6 /Phenol                                                                             0.036  mmol      0.036                                                                              mmol                                    Et.sub.2 AlCl   0.36   mmol      --                                           EtAlCl.sub.2    --               0.36 mmol                                    Benzonitrile    0.04   mmol      0.04 mmol                                    Isopropyl Ether 0.72   mmol      0.72 mmol                                    Initial Temperature                                                                           25°                                                                           C.        40°                                                                         C.                                      Time Until Exotherm                                                                           15     sec.      445  sec.                                    Exotherm        122°                                                                          C.        147°                                                                        C.                                      ______________________________________                                    

EXAMPLES 3-8

In Examples 3 through 8 the procedure described in Example 1 is repeatedexcept that different moderators are added to the activator/monomersolution. In each example the ratio of moles of moderator to moles ofEt₂ AlCl is held constant at 2:1. In Example 3, di-n-butyl ether isadded while in Example 4, diisopropyl ether is used. In Example 5, ethylbenzoate is used while in Example 6, phenylethyl acetate is added. InExample 7, diisopropyl ketone is added. Lastly, in Example 8,tetrahydrofuran is added. In each example, the initial temperature is25° C. (+1° C.). Example 8 is the only case where a solid insolublepolymer is not obtained. The results are listed in Table 4.

                                      TABLE 4                                     __________________________________________________________________________               Example 3                                                                           Example 4                                                                           Example 5                                                                           Example 6                                                                           Example 7                                                                           Example 8                            __________________________________________________________________________    DCPD       72 mmol                                                                             72 mmol                                                                             72 mmol                                                                             72 mmol                                                                             72 mmol                                                                             72 mmol                              WCl.sub.6 /Phenol                                                                        0.036 mmol                                                                          0.036 mmol                                                                          0.036 mmol                                                                          0.036 mmol                                                                          0.036 mmol                                                                          0.036 mmol                           Et.sub.2 AlCl                                                                            0.36 mmol                                                                           0.36 mmol                                                                           0.36 mmol                                                                           0.36 mmol                                                                           0.36 mmol                                                                           0.36 mmol                            Di-n-butyl ether                                                                         0.72 mmol                                                                           --    --    --    --    --                                   Diisopropyl ether                                                                        --    0.72 mmol                                                                           --    --    --    --                                   Ethyl benzoate                                                                           --    --    0.72 mmol                                                                           --    --    --                                   Phenyl ethyl acetate                                                                     --    --    --    0.72 mmol                                                                           --    --                                   Diisopropyl ketone                                                                       --    --    --    --    0.72 mmol                                                                           --                                   Tetrahydrofuran                                                                          --    --    --    --    --    0.72 mmol                            Benzonitrile                                                                             0.04 mmol                                                                           0.04 mmol                                                                           0.04 mmol                                                                           0.04 mmol                                                                           0.04 mmol                                                                           0.04 mmol                            Time until Exotherm                                                                      42 sec.                                                                             15 sec.                                                                             60 sec.                                                                             282 sec.                                                                            160 sec.                                                                            no rxn.                              Exotherm   153° C.                                                                      122° C.                                                                      155° C.                                                                      157° C.                                                                      147°  C.                                                                     --                                   __________________________________________________________________________

EXAMPLES 9-12

In Examples 9 through 12 the activator to catalyst ratios are varied. InExample 9, 0.88 ml of catalyst/monomer solution, described in Example 1is added to 7.1 ml of DCPD containing sufficient Et₂ AlCl and di-n-butylether to give the composition listed in Table 5. In Example 10, 0.44 mlof the same catalyst/monomer solution as used in Example 9 is added to7.5 ml of the same activator/monomer solution used in Example 9, to givethe final composition listed in Table 5. In Example 11, 4.0 ml of acatalyst/monomer solution prepared by mixing 20 ml of DCPD with 1.5 mlof a 0.1M WCl₆ /phenol solution, is mixed with 4.0 ml of anactivator/monomer solution. In this activator solution there issufficient Et₂ AlCl to give a DCPD to alkylaluminum ratio of 100:1 andsufficient di-n-butyl ether to give a di-n-butyl ether to aluminum ratioof 2:1. In Example 12, 4.0 ml of the catalyst/monomer solution used inExample 11 is mixed with 2.0 ml of DCPD and 2.0 ml of theactivator/monomer solution used in Example 11. In each case a solid,insoluble polymer is formed. The results of these reactions showing avariation in the exotherms due to variations in the Al/W ratio, arelisted in Table 5.

                  TABLE 5                                                         ______________________________________                                               Example 9                                                                             Example 10                                                                              Example 11                                                                              Example 12                                 ______________________________________                                        DCPD     57.6 mmol 57.6 mmol 57.6 mmol                                                                             57.6 mmol                                WCl.sub.6 /Phenol                                                                      0.029     0.0145    0.029   0.029                                             mmol      mmol      mmol    mmol                                     Et.sub.2 AlCl                                                                          0.29 mmol 0.29 mmol 0.29 mmol                                                                             0.145                                                                         mmol                                     Di-n-butyl                                                                             0.58 mmol 0.58 mmol 0.58 mmol                                                                             0.29 mmol                                ether                                                                         Benzonitrile                                                                           0.033     0.016     0.033   0.033                                             mmol      mmol      mmol    mmol                                     DCPD/Al  200       200       200     400                                      DCPD/W   2000      4000      2000    2000                                     Al/W     10/1      20/1      10/1    5/1                                      Time to  50 sec.   48 sec.   33 sec. 43 sec.                                  Exotherm                                                                      Exotherm 153° C.                                                                          120° C.                                                                          145° C.                                                                        168° C.                           Percentage                                                                             3.0       4.7       3.0     1.5                                      Residual                                                                      DCPD in                                                                       polymer                                                                       product                                                                       ______________________________________                                    

EXAMPLES 13-15

In Examples 14-15 a small amount of a polar material is added to thecatalyst/monomer solution in order to illustrate the effect of polarmaterial on shelf-life. In Example 13, a catalyst/monomer solution isprepared by adding 2.0 ml of a 0.1M tungsten containing catalystsolution, as described in Example 1, to 20 ml of DCPD in a nitrogenpurged tube. This mixture gelled to a non-flowing material within 24hours. In Example 14, the same procedure is carried out except that 0.03ml of benzonitrile is added, giving a final benzonitrile to tungstenhalide ratio of 1.5:1. This mixture does not gel and is catalyticallyactive after 4 weeks. Example 15 illustrates the result whentetrahydrofuran is added to give a tetrahydrofuran to tungsten halideratio of 1.5:1. Again, a greatly improved storage stability is observed.The results are listed in Table 6.

                  TABLE 6                                                         ______________________________________                                                  Example 13                                                                             Example 14 Example 15                                      ______________________________________                                        DCPD        130    mmol    130  mmol  130  mmol                               WCl.sub.6 /Phenol                                                                         0.2    mmol    0.2  mmol  0.2  mmol                               Benzonitrile                                                                              --         0.3    mmol  --                                        Tetrahydrofuran                                                                           --         --         0.3  mmol                                   Condition after                                                                           gelled     low viscosity                                                                            low viscosity                               24 hours                                                                      Condition after                                                                           gelled     low viscosity                                                                            low viscosity                               4 weeks                                                                       Activity after                                                                            gelled     acceptable acceptable                                  4 weeks                                                                       ______________________________________                                    

EXAMPLES 16-18

In Examples 16-18, the concentration of di-n-butyl ether incorporatedinto the activator/monomer solution to serve as a moderator is varied.In Example 16, the procedure used in Example 1, is followed with theexception that 0.078 ml of n-butyl ether is substituted for thediisopropyl ether. This gives a final ratio of di-n-butyl ether toalkylaluminum of 1.5:1. In Example 17, the procedure is repeated exceptthat 0.156 ml of di-n-butyl ether is added, giving a final ether/Alratio of 3:1. In Example 18, sufficient di-n-butyl ether is added tobring the final ether to alkylaluminum ratio to 5:1. All the reactionsin Table 5 are initiated at 25° C. In each case a solid, insolublepolymer is formed. The results of the reactions are listed in Table 7.

                  TABLE 7                                                         ______________________________________                                                 Example 16                                                                             Example 17  Example 18                                      ______________________________________                                        DCPD       57.6   mmol    57.6 mmol   57.6 mmol                               WCl.sub.6 /Phenol                                                                        0.029  mmol    0.029                                                                              mmol   0.029                                                                              mmol                               Et.sub.2 AlCl                                                                            0.29   mmol    0.29 mmol   0.29 mmol                               Di-n-butyl ether                                                                         0.43   mmol    0.86 mmol   1.45 mmol                               Benzonitrile                                                                             0.033  mmol    0.033                                                                              mmol   0.033                                                                              mmol                               Ether/Al   1.5            3.0         5.0                                     Elapsed time                                                                             36     sec.    55   sec.   75   sec.                               until exotherm                                                                Exotherm   150°                                                                          C.      158°                                                                        C.     159°                                                                        C.                                 ______________________________________                                    

EXAMPLES 19-21

In Examples 19-21, the level of Et₂ AlCl used in the polymerization ofDCPD are varied. In Example 19, 18.5 ml of DCPD was mixed under N₂ with1.5 ml of a 1.0M solution of Et₂ AlCl in DCPD and with 0.55 ml ofdi-n-butyl ether. Then in a N₂ purged tube 8.9 ml of thisactivator/monomer solution is mixed with 1.1 ml of a catalyst/monomersolution as described in Example 1. In Example 20, 4.5 ml of theactivator/monomer solution used in Example 19 is combined with 4.4 ml ofDCPD and 1.1 ml of the catalyst/monomer solution used in Example 20. InExample 21, 2.5 ml of the activator/monomer solution used in Example 19is combined under N₂ with 6.4 ml of DCPD and 1.1 ml of thecatalyst/monomer solution used in Example 19. The final compositions ofthese reaction mixtures are listed in Table 8. All reactions areinitiated at 25° C.

                  TABLE 8                                                         ______________________________________                                                  Example 19                                                                             Example 20 Example 21                                      ______________________________________                                        DCPD        72     mmol    72   mmol  72   mmol                               WCl.sub.6 /Phenol                                                                         0.036  mmol    0.036                                                                              mmol  0.036                                                                              mmol                               Et.sub.2 AlCl                                                                             0.72   mmol    0.36 mmol  0.20 mmol                               Di-n-butyl ether                                                                          1.44   mmol    0.72 mmol  0.40 mmol                               Benzonitrile                                                                              0.04   mmol    0.04 mmol  0.04 mmol                               DCPD/Al     100            200        360                                     Di-n-butyl  2/1            2/1        2/1                                     ether/Al                                                                      Elapsed time                                                                              40     sec.    55   sec.  144  sec.                               until exotherm                                                                Exotherm    150°                                                                          C.      151°                                                                        C.    145°                                                                        C.                                 ______________________________________                                    

EXAMPLES 22-25

The effect of impurities on the catalyst system is illustrated inExamples 22 through 25. In Example 22, a 0.007M solution of WCl₆ /phenolin DCPD is prepared by mixing under nitrogen 150 ml of DCPD with 10.8 mlof a 0.1M WCl₆ /phenol solution in toluene and 0.11 ml of benzonitrile.Then 3.0 ml of this solution is mixed under nitrogen with 3 ml of a DCPDsolution containing AlEt₂ Cl at a level DCPD to alkylaluminum of 150:1and di-n-butyl ether at a level of ether to alkylaluminum of 1.5:1.

In Example 23, a 10 ml sample of the catalyst/monomer solution used inExample 22 is mixed with an impurity, 0.036 mmol of H₂ O, added as adispersion in DCPD. One and one-half hours later, 3 ml of this mixtureis mixed under nitrogen with 3.01 of the activator/monomer solutiondescribed in Example 22. The reaction is repeated this time combiningthe activator/monomer solution with the catalyst/monomer solution 18hours after the H₂ O had been added.

Example 24 is done in the same manner as Example 23 with the exceptionthat 0.036 mmol of tert-butyl hydroperoxide is added to a second 10 mlsample of the catalyst solution rather than H₂ O. The reactivity of theresultant mixture is checked 11/2 and 18 hours after the addition of theimpurity. Example 25 is carried out in the same manner with theexception that 0.072 mmol of di-tert-butylperoxide is the impurity addedinitially to 10 ml sample of the catalyst/monomer solution. In everycase a solid, insoluble polymer is formed.

                  TABLE 9                                                         ______________________________________                                                  Exam-  Exam-     Exam-    Exam-                                               ple 22 ple 23    ple 24   ple 25                                    ______________________________________                                        DCPD        43 mmol  43 mmol   43 mmol                                                                              43 mmol                                 WCl.sub.6 /Phenol                                                                         0.021    0.021     0.021  0.021                                               mmol     mmol      mmol   mmol                                    H.sub.2 O   --       0.01      --     --                                                           mmol                                                     tert-butyl- --       --        0.01   --                                      hydroperoxide                  mmol                                           Di-tert-butyl-                                                                            --       --        --     0.02                                    peroxide                              mmol                                    Et.sub.2 AlCl                                                                             0.14     0.14      0.14   0.14                                                mmol     mmol      mmol   mmol                                    Added       0        0.5/1     0.5/1  1/1                                     Impurity/W                                                                    Induction Time                                                                            31 sec.  50 sec.   98 sec.                                                                              33 sec.                                 after                                                                         11/2hrs.                                                                      Exotherm after                                                                            173° C.                                                                         171° C.                                                                          168° C.                                                                       171° C.                          11/2hrs.                                                                      Induction time                                                                            36 sec.  98 sec.   266 sec.                                                                             73 sec.                                 after 24 hrs.                                                                 Exotherm after                                                                            170° C.                                                                         170° C.                                                                          155° C.                                                                       169° C.                          24 hrs.                                                                       ______________________________________                                    

EXAMPLES 26-33

In each of Examples 26-33, polymerized dicyclopentadiene is made by RIMprocessing using a standard RIM machine. The following descriptionillustrates the procedure for molding. First the desired amount ofcatalyst mixture and activator dicyclopentadiene is charged to two 2gallon tanks. The tanks are located on different sides of the RIMmachine: the tank on the A side is the one to which the activatormixture is added and the tank on the B side is the one to which thecatalyst solution is added. If desired, rubber and/or organic resins areadded as a predissolved solution in dicyclopentadiene. Also solidfillers are added, if desired.

The tanks are then closed off and placed under a nitrogen atmosphere.Sufficient Et₂ AlCl is in the activator solution feed tank (the A tank)to bring the alkylaluminum concentration to 0.048M and sufficientdi-n-butyl ether present to achieve an ether to alkylaluminum ratio of1.5:1. Sufficient WCl₆ /phenol to bring the concentration of thecatalyst in the catalyst side (B side) to 0.007M is present in thecatalyst solution feed tank (B tank). The catalyst solution is preparedas a 0.1M solution in toluene. All transfers are done in a way topreclude the entrance of oxygen or moisture into the system. Thesolution are continuously thoroughly blended in their respective tanks.

The mixing of the activator solution (A stream) and the catalystsolution (B stream) is accomplished using a standard impingement typeRIM mixhead. The ratio of the activator/monomer solution mixed withcatalyst/monomer solution is 1:1. The impingement mixing is accomplishedby passing both the solutions through orifices 0.032" in diameter at aflow rate approximately 80 ml/sec. This required pumping pressure ofapproximately 1000 psi.

The resulting mixture flows directly into a mold heated between 50° C.and 60° C. The mold is made out of aluminum and is chrome plated. Themold has a flat cavity which forms a plaque sample 10"×10"×1/8" thick. Aclamping force of 1.5 tons is used to keep the mold closed. The finishedsamples are removed at various times after mold filling ends.

In Example 26, the outlined molding procedure is followed where there isadded 10 wt% added styrene-butadiene-styrene rubber (Kraton no. 1102manufactured by Shell Chemical Co). The sample is removed from the moldafter 2 minutes. In Example 27 a material of the same composition asExample 26 is produced. This time the mold is opened 30 seconds afterthe combined streams are injected. The surface features of Example 27are noticably better than those of Example 26. In Example 28, 10 wt% ofa thermally polymerized dicyclopentadiene resin is added in addition toboth the catalyst/monomer and the activator/monomer solutions inaddition to the styrene-butadiene-styrene rubber.

Various inorganic fillers are incorporated into the dicyclopentadienepolymer by adding equal amounts to both the catalyst/monomer and theactivator/monomer solutions. In Example 29, samples are made containing33 wt% 1/8" milled glass (P117B grade of Owens Corning Co.). Thesesamples are made by initially slurrying the glass into both solutions ofthe catalyst/monomer and the activator/monomer. Otherwise, thesesolutions are identical to those used in Example 28. In Example 30 acomposition consisting of 10 wt% wollastonite is made by adding thefiller to a formulation identical to that described in Example 28. InExample 31 the same procedure is followed as in Example 30 except that a33 wt% level of wollastonite is employed. In Example 32, 25 wt%wollastonite is added to the formulation described in Example 27. Ineach case a solid, insoluble polymer is formed. Representativeproperties of Examples 26-32 are listed in Tables 10 and 10A.

Example 33 is a RIM processed poly(DCPD) made without any rubberadditives.

                                      TABLE 10                                    __________________________________________________________________________                     Example 26                                                                          Example 27                                                                          Example 28                                                                          Example 29                                 __________________________________________________________________________    Resin Composition                                                             % cyclopentadiene resin                                                                        --    --    10    10                                         % Kraton 1102    10    10    10    10                                         % DCPD           90    90    80    80                                         Filler Composition                                                            wt % 1/8" milled glass                                                                         --    --    --    33                                         wt % wollastonile                                                                              --    --    --    --                                         Tensile Properties                                                            Strength (psi)   --    4,860 5,230 --                                         Modulus (psi)    --    262,000                                                                             257,000                                                                             --                                         Elongation at yield (%)                                                                        --    4.0   4.0   --                                         Flexural Properties                                                           Strength (psi)   7,400 8,600 --    8,200                                      Modulus (psi)    235,000                                                                             250,000                                                                             --    526,000.sup.2                              Impact Properties                                                             Notched Izod (ft #/in. notch)                                                                  13.2  10.5  11.0  2.7                                        Plate Impact at 5000"/min. (ft. #)                                            23° C.    21.0  --    --    --                                         0° C.     15.7  --    --    --                                         -20° C.   12.3  --    --    --                                         Heat Deflection Temperature                                                                    --    65°                                                                          64°                                                                          81°                                 at 264 psi (°C.)                                                       Coefficient of Thermal                                                                         --    6.0 × 10.sup.-5                                                               --    3.2 × 10.sup.-5                      Expansion (in/in °F.).sup.2                                            Linear Mold Shrinkage.sup.2 (%)                                                                2.6   3.5   3.1   1.0                                        Percentage Residual Monomer                                                                    3.0   3.0   3.0   0.03                                       __________________________________________________________________________     .sup.1 Value in the direction parallel to the direction of flow.              .sup.2 Value is the average of the values obtained perpendicular to the       direction of flow and parallel to the direction of flow.                 

                                      TABLE 10A                                   __________________________________________________________________________                     Example 30                                                                          Example 31                                                                          Example 32                                                                          Example 33                                 __________________________________________________________________________    Resin Composition                                                             % cyclopentadiene resin                                                                        10    10    --    --                                         % Kraton 1102    10    10    10    --                                         % DCPD           80    80    90    100                                        Filler Composition                                                            wt % 1/8" milled glass                                                                         --    --    --    --                                         wt % wollastonile                                                                              10    33    25    --                                         Tensile Properties                                                            Strength (psi)   4,700 --    4,290 5,050                                      Modulus (psi)    426,000.sup.1                                                                       --    683,000.sup.1                                                                       270,000                                    Elongation at yield (%)                                                                        3.0   --    2.0   3.4                                        Flexural Properties                                                           Strength (psi)   9,000 8,400 8,300 8,400                                      Modulus (psi)    390,000.sup.2                                                                       670,000.sup.2                                                                       480,000.sup.2                                                                       270,000                                    Impact Properties                                                             Notched Izod (ft #/in. notch)                                                                  2.0   2.9   --    2.3                                        Plate Impact at 5000"/min. (ft. #)                                            23° C.    11.2  --    11.3  --                                         0° C.     12.0  --    11.8  --                                         -20° C.   11.9  --    12.7  --                                         Heat Deflection Temperature at                                                                 69°                                                                          --    79°                                                                          60°                                 264 psi (°C.)                                                          Coefficient of Thermal                                                                         5.2 × 10.sup.-5                                                               --    3.8 × 10.sup.-5                                                               --                                         Expansion (in/in °F.).sup.2                                            Linear Mold Shrinkage .sup.2 (%)                                                               1.6         1.0                                              1.5 -                                                                         Percentage Residual Monomer                                                                    0.1   0.03  0.08  3.0                                        __________________________________________________________________________     .sup.1 Value in the direction parallel to the direction of flow.              .sup.2 Value is the average of the values obtained perpendicular to the       direction of flow and parallel to the direction of flow.                 

EXAMPLE 34

A catalyst component is prepared in the following manner:

In an argon filled glove box, 3.96 g. of WCl₆ is weighed into a 10 oz.bottle. The bottle is then capped. In another 10 oz. bottle, 2.21 g. (10mmol) of nonylphenol is added. This bottle is then capped and spargedwith nitrogen for 20 minutes. The nonylphenol is then dissolved in 100ml. of toluene, and the resulting solution is transferred by cannula tothe bottle containing WCl₆. After marking the solvent level, the bottleis stirred and sprayed with nitrogen for one hour. Acetylacetone, 2.0gram (20 mmol) is then added by syringe and the mixture is spargedrapidly and stirred overnight. Toluene is then added to restore thesolvent level and the resulting solution is divided among ten 4"polyethylene tubes that are capped and sparged. These are stored undernitrogen.

An activator component is prepared in the following manner:

A 4" glass polymerization tube is capped and sparged. 8 ml. of tolueneis syringed into the tube. 2.0 ml. of a 1.8M solution of diethylaluminum chloride in toluene is added by a syringe. 0.49 grams of butylether is then added by syringe.

The polymerization is accomplished in the following manner:

A 15×125 mm test tube is capped with a rubber stopper and sparged withN₂. The tube is then charged with 5 ml. of DCPD. 0.19 ml. of thecatalyst component and 0.038 grams of butyl ether are added by syringe.Then, 0.15 ml. of the activator component was added by syringe and thesample is shaken several times to mix the components. The mixture isallowed to stand and polymerize.

The percent gel swell is determined by the following method:

A 5 gram sample of the polymer was broken out of its test tube andsliced into approximately 1 cm.×1.3 cm. diameter cylinders. Each slicewas then weighed and placed on a stainless steel wire. The wire andsample are hung in about 50 ml. of toluene in a 1 liter round bottomflask and the toluene is allowed to reflux overnight. After cooling, thesamples are removed from the flask, patted dry, and weighed. Percent gelswell is determined according to the following equation: ##EQU1##

It is found that the sample has a percent swell of 110%.

EXAMPLE 34A

The procedure of Example 34 is followed except that a noncycloolefinsolvent free mixture of WCl₆ and WCl₄ O in a 1:1 ratio stabilized by2,4-pentanedione is used as the catalyst in place of WCl₆ andpolymerzation is by injection of a mixture of half of the DCPD and thecatalyst as a mixture and simultaneous injection of a mixture of half ofthe DCPD and the activator component as a mixture. Both DCPD mixturesare injected into a mold to form a flat plate of substantiallycrossliked solid thermoset polymer product. The procedure of Example 34Ais repeated with the addition of 20% milled glass.

Polymer Properties

The product polymers of the invention as produced in Example 34A has anunusual balance of high modulus along with low residual monomer and goodimpact properties (Table 11). Preferably, the product polymers have lessthan one percent and more preferably less than 0.5 percent solvent otherthan residual monomer. Residual monomer is preferably less than twopercent. The flexural modulus for unfilled polymer is 1,790 to 2,070MPa, which is above typical properties for other RIM materials. MParepresenting 1000 pounds per square inch absolute pressure. Addition of20% milled glass raises the modulus to about 2,760 MPa in the mold flowdirection and 2,480 MPa in the perpendicular direction. The somewhatdifferent properties are due to glass fiber alignment. Higher levels ofglass are possible, with the maximum determined by equipmentlimitations. Other fillers such as flaked glass, wollastonite, andcalcium carbonate have also been successfully employed.

The falling-weight impact for unfilled material is 13 to 16 joules. Thisdecreases to only 11 to 13 joules at -29° C. Impact failure is byductile break at room temperature and approaches the brittle/ductiletransition region at -29° C. The impact for 20% milled glass-filledmaterial is 11 to 13 joules at both ambient temperatures and -29° C. Inthis case, the low-temperature failure is by brittle fracture.

Poly(dicyclopentadiene) has a glass transition temperature of 90° C.Heat sag values, which are important for automotive applications,average about 15 mm parallel to the flow direction and 23 mmperependicular to flow in a 20% glass-filled system. Coefficients oflinear expansion are similar to those of other plastics.

In addition to beneficial physical properties, poly(dicyclopentadiene)exhibits excellent paintability characteristics. This is somewhatsurprising considering the hydrophobic nature of the polymer.Formulations to provide flame-retardant properties have also beendeveloped.

                                      TABLE 11                                    __________________________________________________________________________    Poly(dicyclopentadiene) Properties                                                             Direction      20% Milled                                                     to Flow Unfilled                                                                             Glass.sup.(a)                                 __________________________________________________________________________    Flexural modulus, MPa                                                                          Parallel                                                                              2,070  2,900                                                          Perpendicular  2,480                                         Flexural strength, MPa                                                                         Parallel                                                                              62     62-76                                                          Perpendicular  62                                            Tensile modulus, MPa     1,620                                                Tensile strength, MPa                                                                          Parallel                                                                              34     31                                            Tensile elongation, %                                                                          Parallel                                                                              80     25                                            Glass transition temperature, °C.                                                               90                                                   Heat sag, 152 mm OH,                                                                           Parallel                                                                              61     10-20                                         1 hr., 135° C., mm                                                                      Perpendicular  15-30                                         Coefficient of linear                                                                          Parallel                                                                              37 × 10.sup.-6                                                                 17 × 10.sup.-6(b)                       expansion, mm/mm/° C.                                                                   Perpendicular  34 × 10.sup.-6(b)                       Mold shrinkage, cm/cm                                                                          Parallel                                                                              0.035  0.008                                                          Perpendicular  0.021                                         Falling weight impact,                                                        joules, 23° C.    13-16  11-13                                         -29° C.           11-13  11-13                                         Flash point of percent   0.2    0.04                                          residual monomer                                                              Catalyst mixture with DCPD                                                                             101    101                                           Activator mixture with DCPD                                                                            100    100                                           __________________________________________________________________________     .sup.(a) 1/16 in. OCF 737.                                                    .sup.(b) Retained on recycle.                                            

Copolymers

By the addition of comonomers, the glass transition temperature (Tg) ofpolydicyclopentadiene made by ring-opening polymerization is raised.Included in the comonomers which are effective are comonomers whichincrease the crosslink density of the polymer, or increase the"stiffness" of the backbone chain of the polymer. Effective comonomersinclude substituted norbornenes which contain polar functional groupssuch as esters of carboxylic acids and also norbornene derivatives whichare nonpolar hydrocarbons.

This results in copolymers which have a higher maximum use temperaturethan the homopolymer. These copolymers are more suited for applicationswhere the plastic part made from the polymer must retain its propertiesat temperatures near 100° C., for applications where the part must bepainted and the paint must be baked after application in an oven for ashort period of time, or for applications where the plastic part must beheated in an oven for a short period of time to post-cure the polymer.

The glass transition temperature (Tg) of a polymer is defined as thetemperature at which the modulus of the polymer decreases very rapidlyas the polymer undergoes a transition from the glassy state to therubbery state. In general, the glass transition temperature of a polymerwill be raised by either increasing the crosslink density of the polymeror by increasing the stiffness of the chains in the backbone of thepolymer. The crosslink density of a polymer may be determined byswelling the sample in a suitable solvent and then drying it. Theaverage molecular weight between crosslinks can be calculated from theamount the polymer swells. The molecular weight between crosslinks canalso be calculated by dynamic mechanical analysis from the storagemodulus (G') above the sample's Tg. The relative crosslink density oftwo similar polymer samples can also be determined with swellingexperiments. The more highly crosslinked a polymer is, the less it willswell relative to another sample of a similar polymer in the samesolvent.

Poly(dicyclopentadiene) formed by ring-opening polymerization in RIM hasbeen found by swelling experiments, and by dynamic mechanicalexperiments, to have approximately one crosslink for every three repeatunits in the polymer chain. In order to raise the Tg of the polymer, acomonomer may be added that will either have two or more strained,reactive double bonds that will open during the polymerization, so thatthe number of crosslinks will be increased, or it will contain four ormore rings so that when it becomes incorporated in the polymer chain,rotation or movement of the resulting backbone will be more constrained,or in other words the chain will be stiffer.

Dicyclopentadiene may be copolymerized with about 0 to 50% by weight ofanother cycloolefin. More preferably the other cycloolefin is from about1 to 30% by weight. Most preferably the other cycloolefin is from about1 to 25% by weight and the cycloolefin is one or more norbornene-typemonomers. Some of the copolymers particularly those having othernorbornene-type monomers have a glass transition temperature (Tg) whichis higher than the Tg for polymerized dicyclopentadiene. Usefulnorbornene-type monomers include the 1:1 Diels-Alder adducts ofcyclopentadiene with norbornene, norbornadiene and 1,5-cyclooctadiene,the adducts of cyclopentadiene with polyfunctional acrylates, such astrimethylolpropane triacrylate, ethylene glycol diacrylate, ethyleneglycol dimethacrylate, 1,4-butane-diol dimethacrylate and 1,4-butanedioldiacrylate, and the 2:1 adduct of cyclopentadiene with diallyl adipate.Other monomers which have two or more strained, reactive double bonds inthe same molecule would also be suitable. Substantial increases in thecrosslink density (as measured by the degree of swelling of thecopolymers) are obtained with copolymers made from DCPD and thecyclopentadiene adducts with norbornadiene, trimethylolpropanetriacrylate, ethylene glycol diacrylate and ethylene glycoldimethacrylate. Excellent results are obtained with the adduct ofcyclopentadiene and norbornadiene.

Preparation of Comonomers1,4,5,8-Dimethano-1,4,4a,5,8,8a-hexahydronaphthalene (DMHN)

DMHN is prepared by reacting bicyclo [2.2.1]-2,5-heptadiene(norbornadiene) with cyclopentadiene according to reaction I as follows:##STR11##

EXAMPLE 35

Norbornadiene (5.0 kg) was charged to a five gallon autoclave whilemaintaining an inert nitrogen atmosphere in the autoclave. DCPD (1.35kg) was then charged to the reactor.

The reactor was then heated to 180° C. over five hours while stirring,and then maintained at 180° C. for sixteen hours. The reactor was thencooled to room temperature, after which the reactor was vented andopened and the contents of the reactor removed. The DMHN was purified bydistillation in a packed column. Excess norbornadiene (BP₇₀ =38° C.) isremoved first by distilling at a pressure of 70 torr. DMHN (BP₁₀ =90°C.) is then purified by distilling at 10 torr to obtain 1.84 kg ofproduct.

Tricyclo [8.2.1.0]trideca-5,11-diene (TTD)

TTD is prepared by reacting 1,5-cyclooctadiene with cyclopentadieneaccording to reaction II as follows: ##STR12##

EXAMPLE 36

Dicyclopentadiene (50 grams) and 150 grams of 1,5-cyclooctadiene wereadded by cannula to a sparged pop bottle. The mixture was then heated to190° C. over 2 hours and then maintained at that temperature for 4 hoursand then allowed to cool. TTD was purified by first distilling ourexcess 1,5-cyclooctadiene at a pressure of 5 torr and then distillingthe TTD (BP₀₅ =80° C.) at 0.03 torr to give 63 grams of product.

Trimethylolpropane-tris-(5-norbornene-2-carboxylate) (TPNC)

TPNC is prepared by reacting trimethylolpropane triacrylate withcyclopentadiene according to reaction III as follows: ##STR13##

EXAMPLE 37

A solution of 14.8 grams of trimethylolpropane triacrylate in 150 ml ofmethylene chloride was sparged with nitrogen for 15 minutes.Cyclopentadiene (42.8 ml, 0.52 moles) was added in one portion bysyringe, after which the mixture was heated to 40° C. for 3 hours. Aftercooling, the methylene chloride and excess cyclopentadiene were removedby rotary evaporator and high vacuum to provide the product.

Ethylene-bis-(5-norbornene-2-carboxylate) (ENC)

ENC is prepared by reacting ethylene glycol diacrylate withcyclopentadiene according to reaction IV as follows: ##STR14##

EXAMPLE 38

A solution of 17.0 g (0.100 moles) of distilled ethylene glycoldiacrylate in 200 ml of methylene chloride was sparged with nitrogen ina 0.5 l reactor. Cyclopentadiene (46 g, 0.70 moles) was added in oneportion by syringe, after which the mixture was heated to 40° C. for 4hours under a nitrogen atmosphere. The mixture was then cooled, afterwhich the methylene chloride and excess cyclopentadiene were removedwith a rotary evaporator. The crude product was purified bychromatography on a column of 100 g of neutral alumina, eluting firstwith 1.5 l of hexane and then with 4 l of a 1:1 mixture of hexane andmethylene chloride. The hexane/methylene chloride was then stripped toprovide the pure ENC.

Ethylene-bis-(2-methyl-5-norbornene-2-carboxylate (EMNC) EXAMPLE 39

EMNC is prepared by first adding a solution of 21.0 g (0.200 moles) ofmethacryloyl chloride in 50 ml of ether to a solution of 26 g (0.39moles) of cyclopentadiene in 50 ml of ether over one hour at 0° C. Themixture was then warmed to room temperature and stirred overnight. Thissolution was then transferred by cannula to a 0° C. solution of 6.10 g(0.983 moles) of ethylene glycol and 25 g (0.32 moles) of pyridine in150 ml of methylene chloride. This mixture was then stirred overnightwhile warming to room temperature. The solution was then decanted awayfrom precipitated salts which were washed with two 50 ml portions ofhexane. The organic layer was washed with 200 ml of 5% KOH in saturatedaqueous NaCl, dried over magnesium sulfate and concentrated on a rotaryevaporator. The crude product was purified by chromatography on aluminaby eluting first with 200 ml of hexane followed by one liter ofmethylene chloride. Evaporation of the methylene chloride provided 12.5grams of EMNC.

1,4-Butane-bis-(2-methyl-5-norbornene-2-carboxylate) (BMNC) EXAMPLE 40

BMNC is prepared by first adding a solution of 15.5 g (0.148 moles) ofmethacryloyl chloride in 25 ml of ether to a solution of 15 g (0.23moles) of cyclopentadiene in 25 ml of ether over one hour at 0° C. Themixture is then warmed to room temperature and stirred overnight. Thissolution is then transferred by cannula to a 0° C. solution of 6.66 g(0.107 moles) of ethylene glycol and 20 g (0.253 moles) of pyridine in180 ml of methylene chloride. This mixture is then stirred overnightwhile warming to room temperature. The solution is then decanted awayfrom precipitated salts which are washed with two 50 ml portions ofhexane. The organic layer is washed with 200 ml of 5% KOH in saturatedaqueous NaCl, dried over magnesium sulfate and concentrated on a rotaryevaporator. The crude product is purified by chromatography on aluminaby eluting first with 100 ml of hexane followed by 600 ml of methylenechloride. Evaporation of the methylene chloride provided 12.5 grams ofBMNC.

Bis-(20Hydroxymethyl-5-norbornene Adipate (HMNA) EXAMPLE 41

A solution of 227.5 grams of adipoyl chloride in 1 liter of ether wascooled to 0° C. in a 3 liter reactor. A solution of 31.7 grams of5-hydroxy-methyl-2-norbornene in 227.5 ml of pyridine was added slowlyover a period of two hours. The mixture was stirred overnight andfiltered. The solids were then washed with hexane which was combinedwith the filtrate and washed with 1 liter of dilute HCl solution, 250 mlof saturated NaCl solution and dried over magnesium sulfate. Afterremoval of solvent and other volatiles, the crude product is purified bychromatography on alumina to give 271 grams of HMNA.

The adduct of cyclopentadiene and norbornene contains only one doublebond and thus will not increase the crosslink density of the resultingcopolymer. However, the comonomer is a tetracyclic monomer so that inthe ring-opened copolymer the repeat unit in the polymer chain willcontain three fused rings. These tricyclic units have considerably lessfree rotation, and therefore less flexibility, than DCPD so that theirpresence results in a stiffer polymer chain and a correspondingly higherTg. Similar results should be obtained with the cyclopentadiene adductsof alkylnorbornenes such as 5-methylnorbornene.

1,4,5,8-Dimethano-1,4,4a,5,8,8a-octahydronaphthalene (DMON)

DMON is prepared by reacting norbornene with cyclopentadiene accordingto reaction V as follows: ##STR15##

EXAMPLE 42

Norbornene (76 g, 0.807 moles) is weighed into a 10 oz bottle which isthen capped and sparged. DCPD (54 ml, 0.439 moles) was added by syringe.The mixture was heated to 180° C. for 16 hours, after which the bottlewas cooled to room temperature and opened. Excess norbornene was removedby distillation after which the product was distilled under nitrogen ina pop bottle to give 41.7 g of DMON.

Preparation of Copolymers Copolymers of DCPD EXAMPLE 43

A 0.1M solution of a tungsten catalyst is prepared by weighing 3.96grams of WCl₆ under nitrogen into a 200 ml bottle. Nonyl phenol (2.21grams, 0.01 moles) dissolved in 100 ml of toluene, that had beendistilled from Na/K alloy under nitrogen, is added, and the mixture isstirred for one hour while sparging with nitrogen. Acetylacetone (2.00grams, 0.02 moles) is then added by syringe and the mixture was stirredovernight while sparging with nitrogen to remove HCl gas.

An aluminum alkyl activator solution is prepared by diluting 2.00 ml(0.00376 moles) of a 1.88M solution of diethylaluminum chloride (DEAC)with 8.00 ml of distilled toluene and 0.64 ml (0.0038 moles) of di-butylether.

Solutions are prepared containing measured mixtures of DCPD and DMHN.Into a 15 mm×125 mm test tube that had been capped with a rubber septumand sparged with nitrogen is syringed 5 grams of one of the solutions ofthe comonomers. The aluminum alkyl activator (0.15 ml, 0.054 mmoles) isadded to the monomers by syringe. Next, 0.15 ml of di-butyl ether wasadded. After a thermocouple probe has been inserted to measure theexotherm of the reaction, 0.19 ml (0.019 mmoles) of 0.1M tungstencatalyst is added and the tube is quickly shaken to mix the reactants.After a short period of time the mixture polymerized into a solidinfusible polymer mass. Table 12 gives values for the % insoluble gel, %swell in toluene, and Tg, as determined by differential scanningcalorimetry, of the copolymers.

                  TABLE 12                                                        ______________________________________                                        wt. % DMHN  % Gel        % Swell  Tg                                          ______________________________________                                         0          97           110      140                                          5          94           67       175                                         10          93           52       187                                         20          93           40       196                                         ______________________________________                                    

EXAMPLES 44 and 45

These examples describe the preparation of a copolymer of 10 wt % DMHNand 90 wt % DCPD by reaction injection molding (RIM). Samples of DCPDcopolymers made by RIM processing were made using a standard RIM machinesupplied by Accuratio Co. of Jeffersonville, Ind. The followingdescription illustrates the standard procedure for molding samples.First the two monomer storage tanks on the machine were closed off andinerted with nitrogen. The tanks are located on different sides of theRIM machine: the tank on the A side is the one to which the activatorwas later added and the tank on the B side is the one to which thecatalyst was later added.

A mixture of 90% DCPD and 10% DMHN, containing 6% by weight of Stereon720 styrene-butadiene rubber, was added to both tanks. If desired, solidfillers such as milled glass fiber or Wollastonite can be added.Sufficient diethylaluminum chloride was transferred into the A tank sothat the concentration was 0.048M and sufficient di-n-butyl ether wasadded so that the ether to aluminum ratio was 1.5:1. Next, sufficienttungsten catalyst solution was added to the B side tank to bring theconcentration of catalyst to 0.0071M. All transfers were done and allmaterials were handled in a way to preclude the entrance of oxygen ormoisture into the system. The materials were then thoroughly blended intheir respective tanks.

The mixing of the A stream and the B stream was accomplished using astandard impingement type RIM mixhead. The ratio of theactivator/monomer solution mixed with the catalyst/monomer solution was1:1. The impingement mixing was accomplished by passing both thesolutions through orifices 0.032" in diameter at a flow rateapproximately 80 ml/sec. This required pumping pressures ofapproximately 1000 psi.

The resulting mixture flows directly into a mold heated to between 50°and 60° C. The mold has a flat cavity that forms a plaque sample10"×10"×1/8" thick. The mold was opened and the finished plaque wasremoved approximately 10 to 30 seconds after the mold was filled. InExample 10, the procedure outlined above was followed to give plaquesthat could be removed from the mold in 15 seconds. In Example 11, 1/16"milled glass fiber was added to the monomer solutions so that thesamples contained 20% glass. These samples were made by initiallyslurrying the glass into both the catalyst/monomer and theactivator/monomer solutions. The physical properties for these samplesare shown in Table 13.

                  TABLE 13                                                        ______________________________________                                                         Example 10                                                                            Example 11                                           ______________________________________                                        % Glass Filler      0         20                                              Flex Modulus (kpsi)                                                            23° C.     224       421                                              100° C.     66        187                                              Flex Strength (kpsi)                                                           23° C.     9.6       10.7                                             100° C.     1.4       2.0                                              Plate Impact Energy (ft-lb)                                                    23° C.     8.4       9.1                                              -29° C.     3.8       9.0                                              ______________________________________                                    

Copolymers of DCPD and TTD EXAMPLE 46

The procedure of Example 9 is followed except that TTD is used as thecomonomer with DCPD. A solid infusible polymer mass was obtained. The %insoluble gel, % swell in toluene and Tg, as determined by dynamicmechanical analysis, for these copolymer samples are shown in Table 14.

                  TABLE 14                                                        ______________________________________                                        wt. % DMHN  % Gel        % Swell  Tg                                          ______________________________________                                         5          99           108                                                  10          99           103                                                  20          98            94      145                                         ______________________________________                                    

Copolymers of DCPD with Ester-Containing Monomers EXAMPLES 47-51

An aluminum alkyl activator solution is prepared by diluting 2.00 ml(0.00376 moles) of a 1.88M solution of diethylaluminum chloride (DEAC)with 8.00 ml of distilled toluene. The procedure of Example 9 isfollowed except that the above aluminum alkyl activator solution is usedand no di-n-butyl ether is added to the monomers. In addition, thesolution of monomers is heated to 60° C. immediately upon addition ofthe tungsten catalyst solution by placing the tube in a 60° C. heatingbath. The comonomer, % comonomer, % insoluble gel, % swell in tolueneand Tg, as determined by dynamic mechanical analysis, for the copolymersare given in Table 15.

                  TABLE 15                                                        ______________________________________                                        Ex-                                                                           ample Comonomer  % Comonomer % Gel % Swell                                                                              Tg                                  ______________________________________                                        47    TPNC        5          95    93     158                                                  10          94    63                                                          20          94    58     165                                 48    ENC         5          95    95                                                          10          94    85                                                          20          92    71     153                                 49    EMNC        5          93    107                                                         10          94    89                                                          20          94    79                                         50    BMNC        5          97    94                                                          10          97    90                                                          20          95    81     138                                 51    HMNA        5          98    100                                                         10          98    87                                                          20          94    76     122                                 ______________________________________                                    

Copolymers of DCPD with DMON EXAMPLE 52

The procedure of Example 43 is followed except that DMON is used as thecomonomer with DCPD in place of DMHN. A solid infusible polymer mass isobtained in all cases. Table 16 gives the % insoluble gel, % swell intoluene, and Tg, as determined by differential scanning calorimetry forthese copolymer samples.

                  TABLE 16                                                        ______________________________________                                        Comonomer   % Gel        % Swell  Tg                                          ______________________________________                                         5          97           110                                                  10          100          105      160                                         20          98           120      167                                         100         94           102      195                                         ______________________________________                                    

Other features, advantages and specific embodiments of this inventionwill become readily apparent to those exercising ordinary skill in theart after reading the foregoing disclosures. In this regard, whilespecific embodiments of this invention have been described inconsiderable detail, variations and modifications of these embodimentscan be effected without departing from the spirit and scope of theinvention as disclosed and claimed.

EXAMPLES 53-59

In Examples 53-59, substantially crosslinked dicyclopentadiene polymerand copolymer products are formed. The products are formed by mixing acatalyst solution and an activator solution to form a polymerizationsolution which polymerizes to form the polymer products as described inTable 17. The catalyst solution on a molar basis is tungsten catalyst inmonomer. The tungsten catalyst is made as follows: t-butanol is stirredwith 20 grams of WCl₆ in 70 ml of dry toluene under N₂ atmosphere in at-butanol to WCl₆ molar ratio of 0.50 to form a 0.841M catalyst solutionof WCl₆ and WOCl₄. The molar ratio of WCl₆ to WOCl₄ formed is about 3to 1. 11.1 grams of nonyl phenol in 30 ml of toluene is then added. 10.1grams of 2,4-pentanedione is then added by syringe. This solution isthen sparged 18 hours with N₂ to remove HCl. 10 ml of monomer is thenadded to 0.30 ml of the catalyst solution. The monomer and catalystsolution is then warmed at 35° C. for 24 hours while sparging withnitrogen to evaporate the toluene and phenol to form a substantiallysolvent free monomer solution of catalyst. The activator solution isprepared by combining under N₂ 8.6 ml of monomer and 0.39 ml of 1.0Mtri-n-octyl-aluminum in monomer.

In Examples 53-59, the activator solution also includes 0.1 ml ofbis-(2-methoxyethyl) ether. The exotherm of polymerization occurs inabout 15 to 25 seconds after mixing 5.0 ml the catalyst in monomersolution to 5.0 ml of the activator in monomer solution. Both solutionsare initially at 25° C. They are intimately mixed in the mixed in themixed and the mixture injected into a mold.

In Examples 53 and 56 flame retardant is added to the catalyst solutionprior to mixing with the activator solution. In Examples 55, 58 and 59milled glass is added to the activator solution prior to mixing with thecatalyst solution. In Examples 56-59 elastomer is added equally to boththe catalyst solution and the activator solution priro to mixing.

                                      TABLE 17                                    __________________________________________________________________________                            Example                                                                       53  54  55  56  57  58  59                            __________________________________________________________________________    Activator to Catalyst ratio                                                                           3.0 3.0 3.0 3.0 3.0 3.0 3.0                           Monomer weight %                                                              DCPD                    100 80  80  95  95  95  95                            DMHN                    --  20  20  5   5   5   5                             Additive                32  --  --  32  --  --  --                            parts flame                                                                   retardant                                                                     N,N'--ethylene-bis-tetrabromophthalimide/Sb.sub.2 O.sub.3 /                   NH.sub.4 BH.sub.4) per 100 parts                                              monomer (by weight)                                                           Weight % residual monomer                                                                             0.1 0.3 0.04                                                                              0.4 0.4 0.05                                                                              0.05                          Tg °C.           140 196 198 175 175 175 175                           Weight % swell          100 40  38  60  60  60  60                            Weight % gell           98  93  99.9                                                                              89.5                                                                              89.5                                                                              89.9                                                                              89.9                          Flexural modulus (psi)  380,000                                                                           300,000                                                                           576,000                                                                           385,000                                                                           245,000                                                                           526,000                                                                           546,000                       Notched Izod            2.1 2.0 2.3 10.5                                                                              8.8 10.2                                                                              8.9                           impact strength                                                               (ft-lb/inch notch)                                                            Filler                  --  --  33  --  --  33  33                            weight % 1/8 inch                                                             milled glass                                                                  Elastomer styrene-butadiene                                                   weight % butyl rubber   --  --  --  6   --  6   --                            weight %                --  --  --  --  10  --  10                            weight % saturated styrene                                                    weight % butadiene-styrene                                                    weight % triblock rubber                                                      __________________________________________________________________________

Rate Moderation By Use of Polar Monomer EXAMPLE 60 Synthesis of2-Hydroxymethyl-5-Norbornene Acetate

Into a solution of 99.2 g of 2-hydroxymethyl-5-norbornene and 50 ml ofchloroform is added dropwise a solution of 84.0 g of acetic anhydride in100 ml of chloroform. This mixture is allowed to stir overnight at roomtemperature, followed by heating at reflux for three hours. The cooledreaction mixture is poured into water and stirred to hydrolyze unreactedacetic anhydride. The layers are separated, the organic phase is dilutedwith an equal volume of hexane, and the mixture repeatedly washed withwater to remove most of the pyridine. A final wash with dilute HClsolution, saturated sodium bicarbonate solution and saturated sodiumchloride solution removes pyridine, acetic acid and water from theorganic phase. Drying over anhydrous magnesium sulfate and removal ofthe solvent on a rotary evaporator affords 137 g of crude product as afaintly yellow, pleasant smelling oil. This is diluted with 2 volumes ofhexane and passed through a 300 g column of neutral alumina, followed bycontinued hexane elution (1 l) until "no more" material was found in theeffluent. Distillation of the hexane and vacuum distillation of theresidue (55° C., 0.8 mm) provides 103.1 g (84%) of the acetate as aclear, colorless oil characteristic fruity odor; ir: 3139, 3061, 2965,2868, 1741, 1361, 1235, 1028, 714 cm⁻¹ ; 60 MHZ NMR (CDCl₃) 2.02 (H₃CCO₂ --).

EXAMPLE 61 Synthesis of 2-Hydroxymethyl-5-Norbornene Adipate

Into a solution consisting of 62.0 of the 5-hydroxymethyl-2-norborneneand 100 ml of pyridine under N₂ cooled to 0° C. is added dropwise asolution of 45.7 g (36.4 ml) of distilled adipoyl chloride (107° C./2mm) in 200 ml of chloroform. The ice bath is removed after addition wascompleted, and the mixture stirred overnight at room temperature. Thereaction mixture is diluted with 2 volumes of hexane and repeatedlywashed with dilute aq. HCl solution to remove the pyridine. This isfollowed by saturated sodium bicarbonate washes, saturated NaClsolution, and drying over anhydrous magnesium sulfate. Removal of thesolvent gives 95.53 g (104%) of crude product as a pleasant smellingyellow oil. The crude product is distilled under vacuum (206°/0.4 mm) togive 93.82 g (82%) of product as a nearly colorless and odorless oil.Dilution of this material with 2 volumes of hexane and elution through250 g of neutral alumina, continued elution with hexane and solventstripping at reduced pressure finally gave a water white product in 75%yield; ir: 3120, 3061, 2965, 2870, 1735, 1170, 714 cm⁻¹.

EXAMPLE 62 Synthesis of Methyl 5-Norbornene-2-Carboxylate

In 100 ml of anhydrous ether at 0° C. is mixed 30 ml of cyclopentadieneand 32 ml of methyl acrylate. The ice bath is removed and the mixtureallowed to stir overnight. The solvent, unreacted methyl acrylate, andcyclopentadiene are removed at ambient temperature at reduced pressure;as less material distilled out of the mixture the pressure is graduallyreduced to 0.5 mm. The desired epimeric mixture of methyl carboxylate isdistilled at 42'-43° and 0.5 mm; ir: 3118, 3060, 2965, 2941, 2862, 1734,1428, 1329, 1264, 1190, 1024, 704, cm⁻¹ ; 60 MHZ NMR: endo/exo=80/20.

The rate of cycloolefin polymerization can be adjusted by use of polarmonomers such as norbornene esters. Copolymers of DCPD and norborneneesters are polymerized in from about one to two and one fourth minuteswithout the addition of a noncycloolefin rate moderate as shown inExamples 63-65 and Table 18. The copolymers have percent by weight gelof from about 88.7 to 99.2 as shown in Table 19.

EXAMPLES 63-65 Catalyst Preparation

In an Argon-filled glove box, 3.96 g of WCl₆ is weighed into one 10 ozpop bottle and 19.80 g into another for preparation of 0.1M and 0.5Msolutions, respectively. These bottles are then removed from the box andplaced in a N₂ filled glove bag. Into one centrifuge bottle is weighed2.00 g of nonylphenol (C₉ PhOH) and 10.00 g into another. The bottlesare then filled with 100.0 ml of toluene (from Na/K), capped and spargedwith N₂ for 30 minutes. The contents of the bottles are transferred viacannula under positive N₂ pressure into their respective WCl₆ bottles toform the 1:1 complexes followed by N₂ sparing overnight to removeevolved HCl. The contents of the 0.1M WCl₆ /C₉ PhOH bottle aredistributed in 9 4" poly tubes (previously N₂ sparged) in a glove bag.The DEAC (Et₂ AlCl) solution is used as received (25% wt in toluene), ora known volume is transferred to a 4" poly tube (previously capped andsparged) and the calculated amount of n-Butyl ether added to form the1:1.1 Al/Bu₂ O complex.

Copolymerization of DCPD and Functional Monomers

A typical procedure for copolymerization of DCPD and an ester comonomeris as follows: Six 1×13 cm test tubes are loaded with the indicatedweight % of functional comonomer, a rubber septum was wired on, and theassembly sparged with N₂ for 10 minutes. Enough dicyclopentadiene isthen added to bring the contents of the tubes to 5.0 g and spargingcontinued for 10 minutes. To each tube immediately prior topolymerization is added 0.03 ml of 1.84M DEAC in toluene, and thecontents thoroughly mixed. A solution of 0.5M WCl₆ /C₉ PhOH in toluene(0.04 ml) is then added, the contents are mixed by multiple inversions(15 sec), a thermocouple probe (soldered into a 14 ga syringe needle)inserted through the top, and the tube placed in a 60° C. oil bath toinitiate polymerization. The times reported in the table are forreaching the exotherm maximum from time of immersion in the oil bath;precision is within the ±10 sec envelope. A sample without catalyst willtake 2 minutes to reach bath temperature from time of immersion.

Gel Swell Determinations on Comonomers

The general procedure used is as follows: A 5 g sample of copolymer isremoved from its test tube (by breaking the glass) and carefully slicedinto 1-2 mm thick sections across the cylindrical axis with a band saw.The burrs are removed, each slice weighed to the nearest milligram, andstrung onto a stainless steel wire taking care to keep them in knownsequence. This is done for each sample at a given comonomer feed. Thewire is made into a closed loop and placed in 50 ml of toluene for eachgram of copolymer. Whereas, in some cases, several loops of copolymerare placed in a single flask of toluene, only those of common functionalmonomer are ever placed together. These flasks are then heated to refluxfor 16 hours (overnight) and cooled. Each loop is successively removedfrom the flask and placed in a small crystallizing dish of freshtoluene. The slices are removed, patted dry, and weighed individually,again taking care not to not to disturb their sequence or to tear theswollen samples. After weighing, they are restrung and placed in aforced draft (N.sub. 2) oven at 135° C. for 16 hours (overnight). Thesamples are reweighed and their gel and swell values calculated.

Two samples are reacted under each set of comonomer composition. Eachsample is then sliced into thin sections for gel/swell determinations.

                  TABLE 18                                                        ______________________________________                                        Copolymerization of Dicyclopentadiene                                         and Functional Monomers.sup.(a)                                               Ex-                                    Time                                   am-                    DCPD/CM    T.sub.max                                                                          tp T.sub.max                           ple  Comonomer (CM)    (wt %)     (°C.)                                                                       (min)                                  ______________________________________                                        63                                                                                  ##STR16##        95/5 95/5 90/10 90/10 80/20 80/20                                                        201 190 206 202 198 198                                                            13/4 11/4 11/2 11/2 11/2 11/2          64                                                                                  ##STR17##        95/5 95/5 90/10 90/10 80/20 80/20                                                        203 204 205 206 197 205                                                            1 1 11/2 11/2 21/4 2                   65                                                                                  ##STR18##        95/5 95/5 90/10 90/10 80/20 80/20                                                        199 199  204 201 203 206                                                           1 1 1 1 11/4 11/4                           Homopolymerization                                                                              100/0      194  3/4                                         of DCPD (Room Tempera-                                                        ture Initiation)                                                         ______________________________________                                         All polymerizations are run with the same concentration of catalysts,         calculated as 2000:1:2.75 Monomer:W:Al based on 5 g of DCPD. All reaction     are run in a 60° C. oil bath except homopolymerization of DCPD         (last entry). Times recorded are from immersion of sample tube in the bat     to the maximum temperature of the exotherm. A tube with no catalyst           requires 2 minutes to reach bath temperature.                            

                  TABLE 19                                                        ______________________________________                                        Gel-Swell Values for Copolymers of DCPD                                       and Functional Monomers                                                       Ex-                   DCPD/    Swell  Gel                                     am-                   CM       (Weight                                                                              (Weight                                 ple  Comonomer (CM)   (wt %)   %)     %)                                      ______________________________________                                        63                                                                                  ##STR19##       95/5 95/5 90/10 90/10 80/20 80/20                                                      153 152 184 144 213 190                                                              95.3 92.8 95.0 93.8 89.1 88.7           64                                                                                  ##STR20##       95/5 95/5 90/10 90/10 80/20 80/20                                                       95 105  86  88  77  75                                                              98.2 98.6 97.9 97.6 94.8 93.8           65                                                                                  ##STR21##       95/5 95/5 90/10 90/10 80/20 80/20                                                      122 113 200 127 186 245                                                              96.0  94.7 97.3 98.9 97.0 99.2          ______________________________________                                    

In Examples 66, 67, 71 and 73, the fluorinated alkyl methacrylatecopolymer surfactant used is FC-740, manufactured by Minnesota Miningand Manufacturing Company.

EXAMPLE 66

The catalyst used is a 1:1 molar mixture of WCl₆ to WCl₄ O as preparedherein above. An aluminum alkyl activator solution that is 1.06M intrioctylaluminum (TNOA), 0.19M in diethylaluminum iodide (DEAI) and1.25M in methoxyethyl ether is prepared by dissolving 85.0 grams ofmethoxyethyl ether, 196.1 grams of TNOA, and 20.00 grams ofdiethylaluminum iodide (DEAI) in 157.3 ml of dicyclopentadiene. Themolar ratio of TNOA to DEAI to methoxyethyl ether is then0.85:0.15:1.00.

Examples 67 through 70 illustrate small scale examples where a cellularpolymer of dicyclopentadiene monomer is formed using a mixture ofdiethylaluminum iodide and trioctylaluminum as catalyst activators wherethe dicyclopentadiene monomer also contains 6 weight percentstyrene-butadiene rubber.

EXAMPLE 67

A catalyst and monomer solution is prepared by mixing under nitrogen 50grams of DCPD that had previously had 3.0 grams of styrene-butadienerubber dissolved in it with 3.8 ml of the 0.1M catalyst solution, 2.5grams of trichlorofluoromethane, and 0.50 grams of fluorinated alkylmethacrylate copolymer.

An activator and monomer solution is prepared by mixing under nitrogen50.0 grams of DCPD that has 3.0 grams of styrene-butadiene rubberdissolved in it with 1.45 ml of 1.25M aluminum alkyl activator solution,2.5 grams of trichlorofluoromethane, and 0.50 grams of fluorinated alkylmethacrylate copolymer.

The catalyst and monomer and activator and monomer were then combinedand mixed rapidly under nitrogen. The mixture was then poured rapidlyinto a vented mold and allowed to polymerize into a cellular polymer.

EXAMPLE 68

The procedure of Example 2 is followed except that ten percent oftrichlorofluoromethane was used as the blowing agent, 0.5 percentfluorinated alkyl methacrylate copolymer surfactant was used and 1.16 mlof the aluminum alkyl activator is used to make up the activator andmonomer solution.

EXAMPLE 69

The procedure of Example 2 was followed except that seven percenttrichlorofluoromethane was used as the blowing agent and 1.40 ml ofaluminum alkyl activator solution is used to make up the activator andmonomer solution.

EXAMPLE 70

The procedure of Example 2 was followed except that 1.51 ml of aluminumalkyl activator solution is used to make up the activator and monomersolution.

EXAMPLE 71

The procedure of Example 3 is used except that fifteen percent methylenechloride was used as the blowing agent and 1.06 ml of aluminum alkylactivator solution is used to make up the activator and monomersolution.

Table 20 shows the polymerization mixtures from which foam products areformed in Examples 66-71.

                                      TABLE 20                                    __________________________________________________________________________    FOAM EXAMPLES                                                                                 Example 67                                                                          Example 68                                                                          Example 69                                                                          Example 70                                                                          Example 71                            __________________________________________________________________________    DCPD (grams)     100  100   100   100   100                                   Tungsten catalyst mmol                                                                        .756  .756  .756  .756  .756                                  Diethylaluminum diodide (mmol)                                                                .272  .218  .262  .280  .198                                  Trioctyl aluminum (mmol)                                                                      1.54  1.234 1.49  1.61  1.12                                  Methoxyethyl ether (mmol)                                                                     1.81  1.452 1.75  1.89  1.32                                  Blowing Agent   CFC13 CFC13 CFC13 CFC13 CH2C12                                Weight percent  5     10    7     5     15                                    Rubber (elastomer)                                                                            SBR   SBR   SBR   SBR   SBR                                   Weight percent  6     6     6     6     6                                     Surfactant      FC-740                                                                              FC-740                                                                              FC-740                                                                              FC-740                                                                              FC-740                                Weight percent  1.0   0.5   1.0   1.0   0.5                                   Density (g/cc)  0.30  0.13  0.21  0.39  0.18                                  __________________________________________________________________________

EXAMPLE 72

This example illustrates a preferred embodiment of the synthesis of acellular cross-linked polymerized dicyclopentadiene via reactioninjection molding where the catalyst system is activated by a mixture oftrioctylaluminum (TNOA) and diethylaluminum iodide (DEAI).

Into two tanks, which have previously been closed and inerted withnitrogen, having a capacity of two gallons each is charged DCPDcontaining 6% by weight of a random styrene-butadiene rubber. SufficientWCl₆ /nonylphenol/acetylacetone catalyst, having a ratio of 1:1:2, inxylene is added to one of the tanks to provide a DCPD:tungsten catalystratio of 1000:1. Next, to the other tank is added sufficienttrioctylaluminum:diethylaluminum iodide:methoxyethyl ether solution,having a molar ratio of 0.85:0.15:1.0 to provide a DCPD:aluminum ratioof 1000:2.4. Fluorinated alkyl methacrylate copolymer surfactant isadded to each tank to achieve a concentration of 0.5 parts per hundred,based on the weight of DCPD. Methylene chloride is then added to eachtank to achieve a concentration of 5.0 parts per hundred, based on theweight of DCPD. All transfers are done in a way to preclude the entranceof oxygen or moisture into the system. The materials are then thoroughlyblended in their respective tanks.

The components of the two tanks are combined in a standard impingementtype RIM mixhead. The ratio of the activator/monomer solution mixed withthe catalyst and monomer solution is 1:1. The impingement mixing isaccomplished by passing both of the solutions through orifices 0.032inch in diameter at a flow rate of approximately 80 ml/sec. Thisrequires pumping pressure of approximately 500 psi to 1000 psi.

The resulting mixture flows directly into a mold heated to between 35°C. and 70° C. The mold is made out of chrome plated aluminum. The moldhas a flat cavity which forms a plaque sample 8 inch×8 inch×3/8 inchthick. The reactants polymerize rapidly in the closed mold, reactionbeing substantially complete in about one minute or less. The mold isopened and a cellular cross-linked poly DCPD is recovered having adensity of 0.55 grams/cc.

EXAMPLE 73

A catalyst and monomer solution is prepared by mixing under nitrogen 400grams of DCPD, 30.7 ml of 0.1M tungsten catalyst solution, 2 grams ofsilica, and 57 grams of trichlorofluoromethane.

An activator and monomer solution is prepared by mixing under nitrogen390 grams of DCPD, 39 grams of styrene-butadiene rubber, 5.49 ml of a0.825M solution of DEAC in DCPD, 15.5 ml of a 0.450M solution of DEAI inDCPD, and 56 grams of trichlorofluoromethane.

171.4 grams of catalyst and monomer solution and 188.6 grams ofactivator and monomer solution were then combined and mixed undernitrogen and poured into a mold. After about one minute the mixturestarts to polymerize and expand into a cellular crosslinked polymer. Thefinal density of the foam is 0.034 grams/cc.

The silica used in Example 8 above is Cab-o-sil EH-5, manufactured byCabot Corp.

EXAMPLE 74

A catalyst and monomer mixture is prepared by mixing under nitrogen 100grams of DCPD, 10 grams of SDP-760 polyethylene powder (SDP-760 fromArco Chemical, 10 grams of methylene chloride, 0.50 grams of fluorinatedalkyl methacrylate copolymer surfactant, and 7.56 ml of 0.1M tungstencatalyst solution.

An activator and monomer solution is prepared by mixing under nitrogen100 grams of DCPD, 10 grams of styrene-butadiene rubber, 10 grams ofmethylene chloride, 0.50 grams of fluorinated alkyl methacrylatecopolymer surfactant, 2.8 ml of a 0.825M solution of DEAC in DCPD, 0.53ml of a 0.450M solution of DEAI in DCPD, and 0.70 grams of butyl ether.

The activator and monomer solution and the catalyst and monomer mixtureare mixed at 40° C. and poured rapidly into a 3 inch×4 inch×9 inch moldat 45° C. where the mixture polymerizes into a cellular polymer having adensity of 0.13 grams/cc.

Examples 75 and 76 preexotherm gelation of the monomer.

EXAMPLE 75

A 0.1M solution of the tungsten catalyst having a 1:1 molar ratio ofWCl₆ to WCl₄ O is used. Nonyl phenol (2.21 grams, 0.01 moles) dissolvedin 100 ml of toluene, that has been distilled from Na/K alloy undernitrogen, is added, and the mixture is stirred for one hour whilesparging with nitrogen. Acetylacetone (2.00 grams; 0.02 moles) is thenadded by syringe and the mixture is stirred overnite while sparging withnitrogen to remove HCl gas.

Polymerizations are conducted in a capped 10 ml vial that has beenpreviously sparged with nitrogen. The vial cap has five small holes init to accommodate a gas line for flushing with nitrogen, a tube forintroducing the monomer mixture, thermocouple leads to measure theexotherm of the sample during the polymerization and the spindle of adigital Brookfield viscometer to measure the viscosity of the sampleduring the polymerization.

A catalyst/monomer solution is prepared by mixing under nitrogen 10.0grams of DCPD and 0.76 ml of the 0.1M catalyst solution. Anactivator/monomer solution is prepared by mixing under nitrogen 10.0grams of DCPD, 0.63M solution of diethylaluminum chloride in toluene,and 0.15 grams of butyl ether.

Polymerization of DCPD is accomplished by simultaneously syringing 4.0ml each of catalyst/monomer solution and activator/monomer solutionthrough a T-shaped tube which is connected to the sample vial. Mixing ofthe two solutions is accomplished by impingement of the two streams uponeach other in the T-shaped tube. After a brief induction period theviscosity of the monomer increased rapidly to greater than 100,000centipoise. After an additional period of time a sharp exotherm isobserved and a solid insoluble polymer was formed. The time that elapseduntil gellation, the time until the exotherm, and the total exotherm areshown in Table 2.

EXAMPLE 76

In this example the procedure of Example 75 is followed except that 0.20ml of a 1.12M solution of trioctylaluminum and methoxyethyl ether inDCPD was added in place of the diethylaluminum chloride and butyl etherto prepare the activator/monomer solution. A solid insoluble polymer isformed. The results are shown in Table 21.

Using the procedure of Examples 77-79 on intricate molds to form solidproducts.

EXAMPLE 77

This example illustrates delaying the gellation of the monomer by usinga mixture of diethylaluminum chloride and diethylaluminum iodide.

The procedure of Example 75 is followed except that 0.57 ml of a 0.36Msolution of diethylaluminum chloride in toluene and 0.054 ml of a 0.42Msolution of diethylaluminum iodide in toluene are used in place of 0.63ml of diethylaluminum chloride to prepare the activator/monomersolution. A solid insoluble polymer is obtained. The time untilgellation, the time until exotherm, and the exotherm of the sample aregiven in Table 2.

EXAMPLE 78

This example illustrates delaying the gellation of the monomer by usinga mixture of trioctylaluminum and diethylaluminum iodide.

The procedure of Example 75 is followed except that 0.47 ml of asolution that was 0.34M is trioctylaluminum, 0.06M in diethylaluminumiodide, and 0.40M in methoxyethyl ether in DCPD was used in place of thediethylaluminum chloride and butyl ether to make up theactivator/monomer solution. A solid insoluble polymer was obtained. Thetime until gellation, the time until exotherm, and the exotherm of thesample are given in Table 21.

                                      TABLE 21                                    __________________________________________________________________________               Example                                                                       75     76     77     78                                            __________________________________________________________________________    DCPD       60.5 mmol                                                                            60.5 mmol                                                                            60.5 mmol                                                                            60.5 mmol                                     Tungsten catalyst                                                                        .0303 mmol                                                                           .0303 mmol                                                                           .0303 mmol                                                                           .0303 mmol                                    Et.sub.2 AlCl                                                                            .0908 mmol    .0818 mmol                                           Octyl.sub.3 Al    .0908 mmol                                                  Et.sub.2 AlI             .00909 mmol                                                                          .0113 mmol                                    Octyl.sub.2 AlI                                                               Butyl Ether                                                                              0.454 mmol    0.454 mmol                                           Methoxyethyl ether                                                                              .0908 mmol    .0756 mmol                                    Gellation time                                                                           10 sec 20 sec 29 sec 24 sec                                        Time until exotherm                                                                      48 sec 38 sec 30 sec 25 sec                                        Exotherm   162° C.                                                                       163° C.                                                                       165° C.                                                                       164° C.                                __________________________________________________________________________

In Example 79, sufficient methoxyethyl ether is added so that the finalmethoxyethyl ether/alumina ratio was 3/1. In each case, a solidinsoluble cross-linked polymer is obtained. The times until gellation,the times until exotherm, and the exotherms of the samples are given inTable 22. In each case, a solid insoluble cross-linked polymer isobtained. The times until gellation, the times until exotherm, and theexotherms of the samples are given in Table 22.

EXAMPLE 79

In Example 79 the procedure of Example 75 is followed except that 0.54ml of a solution that is 0.36M in trioctylaluminum, 0.063M indioctylaluminum iodide, and 0.42M in methoxyethyl ether in toluene isused in place of the diethylaluminum chloride and the butyl ether tomake up the activator/monomer solution. A solid insoluble polymer isobtained. The time until gellation, the time until exotherm, and theexotherm of the sample are given in Table 22.

                  TABLE 22                                                        ______________________________________                                        Example 79                                                                    ______________________________________                                        DCPD                 60.5   mmol                                              Tungsten catalyst    .0303  mmol                                              Et.sub.2 AlCl                                                                 Octyl.sub.3 Al       .0773  mmol                                              Et.sub.2 AlI                                                                  Octyl.sub.2 AlI      .0136  mmol                                              Butyl Ether                                                                   Methoxyethyl ether   .0909  mmol                                              Gellation time       24     sec                                               Time until exotherm  26     sec                                               Exotherm             156°                                                                          C.                                                ______________________________________                                    

The solid insoluble polymers formed in Examples 75-79 are substantiallycrosslinked having notched Izod impact strengths of at least 1.5ft-lb/in notch; a flexural moduli of at least 150,000 psi at ambienttemperature (about 70° F.); and a percent gel swell determined after thepolymer is immersed in toluene for two hours at 100° C. of less thanabout 200%.

Polymerization by the present invention may be carried out in any mold.For example, cyclic olefin monomer may be polymerized in accordance withthe present invention by reaction injection molding, pour molding orspray molding.

The substantially crosslinked polymerized dicyclopentadiene of thepresent invention provides the beneficial flex creep properties. Theweight percentage swelled in toluene is the amount of absorbed tolueneas a percent by weight of the original substantially crosslinkedpolymerized dicyclopentadiene. The percent of flexural creep strain isthe change in length of the substantially crosslinked polymerizeddicyclopentadiene as a percentage of the original length of the sampletested.

The polymeric product of Example 77 has a percent gel swell of 110%. Thenumber of monomer units between crosslinks in the polymeric product ofExample 77 is about 10.

The polymeric composition of the present invention comprisingsubstantially crosslinked polymerized units of dicyclopentadiene ispreferably characterized as having a percent gel swell, determined afterthe polymer is immersed in toluene for two hours at 100° C., of fromabout 15 to about 200. More preferably, the polymeric composition of theinvention is characterized as having a percent gel swell of from about30 to about 180. Most preferably, the polymeric composition of theinvention is characterized as having a percent gel swell of from about50 to about 150.

The polymeric composition of the present invention comprisingsubstantially crosslinked polymerized units of dicyclopentadiene ispreferably characterized as having from about 1 to about 30 monomericunits between crosslinks. More preferably, the polymeric composition ofthe invention is characterized as having from about 2 to about 24monomeric units being crosslinks. Most preferably, the polymericcomposition of the invention is characterized as having from about 3 toabout 16 monomeric units between crosslinks.

The product density may vary from about 1.2 g/ml with some filler toabout 0.04 g/ml. The ultra low density foam product of the invention isnovel at densities below 0.2 g/ml, for example, 0.18 g/ml and lower.

Preferably, in the substantially crosslinked polymer composition of theinvention the average distance between crosslinking is preferably fromabout one to about 65 monomer units and more preferably from one monomerunit to about 20 monomer units. This range of crosslinking in thecrosslinking polymer is characterized as having a gel swell determinedafter the crosslinked polymer is immersed in toluene for two hours at100° C. of from about 15% to about 200%. Also, this range ofcrosslinking in the crosslinked polymer is characterized as having aflexural creep strain of from about 0.3% to about 4.5% after 100 hoursof exposure to a 2000 psi stress load at 150° F.

Other features, advantages and specific embodiments of this inventionwill become readily apparent to those exercising ordinary skill in theart after reading the foregoing disclosures. In this regard, whilespecific embodiments of this invention have been described inconsiderable detail, variations and modifications of these embodimentscan be effected without departing from the spirit and scope of theinvention as disclosed and claimed.

What I claim and desired to protect by Letters Patent is:
 1. Apolymerization catalyst composition comprising: ##STR22## wherein R isan alkyl group having 3 to 20 carbon atoms; R₁ and R₂ are independentlyhydrogen, an alkyl or alkoxy of from 1 to 5 carbons; m is 4 or 6 and nis 0 or
 1. 2. The composition of claim 1 wherein n is 1; m is 4 and R isnonyl and the molar ratio of WCl_(m) O_(n) to ##STR23## is from about1:1 to about 1:3.
 3. The composition of claim 1 further comprising acompound selected from the group consisting of 2,4-pentanedione anddiglyme.
 4. The composition of claim 1 further comprising a cycloolefin.5. The composition of claim 1 further comprising a cycloolefin and themolar ratio of WCl_(m) O_(n) to ##STR24## is from about 1:1 to about1:5.
 6. The composition of claim 4 wherein said cycloolefin isdicyclopentadiene said dicyclopentadiene being at least 98 percent pureprior to addition to said composition.
 7. The composition of claim 5wherein said cycloolefin is dicyclopentadiene said dicyclopentadienebeing at least 98 percent pure prior to addition to said composition. 8.The catalyst composition of claim 1 wherein said WCl_(m) O_(n) is amixture of WCl₄ O and WCl₆ in a molar ratio of WCl₄ O to WCl₆ from 1:9to 2:1.
 9. A polymerization catalyst composition of the formula##STR25## wherein R is an alkyl group of from 1 to 20 carbon atoms; R₁is hydrogen or an alkyl group of from 1 to 5 carbon atoms; R₂ ishydrogen or an alkyl group of from 1 to 5 carbon atoms; R₃ is hydrogenor an alkyl group of from 1 to 5 carbon atoms; R₄ is hydrogen or analkyl group of from 1 to 5 carbon atoms.
 10. The composition of claim 9further comprising a cycloolefin.
 11. The composition of claim 10wherein said cycloolefin is dicyclopentadiene.
 12. A polymerizationcatalyst composition comprising: ##STR26## wherein m is 4 or 6; n is 0or 1; and R₁ and R₂ are independently hydrogen, an alkyl or alkoxy offrom 1 to 5 carbons.
 13. The composition of claim 12 wherein n is 1 andm is
 4. 14. The composition of claim 13 further comprising a cycloolefinand wherein the molar ratio of WCl_(m) O_(n) to ##STR27## is from about1:1 to about 1:5.
 15. The composition of claim 14 wherein saidcycloolefin is dicyclopentadiene, said dicyclopentadiene being at least98 percent pure prior to addition to said composition.